Whether through injuries and/or downright lousy performances, many highly-rated prospects in the A's system failed to live up to expectations last season. Here is a brief look at some of these underachievers from yesteryear that might be primed for Comeback Player of the Year honors:

C/DH - Landon Powell

There's no question that Powell should be at the top of this list. When healthy, there is simply not many players in the entire minor leagues that can offer what Powell can at the catching position.

After coming out of college with a major knee injury  in 2004, missing all of 2005 recovering and sputtering a bit in 2006, Powell finally put it all together last season by blistering Texas League pitching (OPS-ing .893) and homering in his first three games at Triple-A before re-tearing his ACL and being shelved for the season. With the emergence of Kurt Suzuki, the fallout from Powell's second major injury in the last few years has not been as serious as it probably should be.

When healthy, Powell is a major asset to any team he is on: he can switch-hit with power from both sides of the plate (30 homers in the past two years), work walks (15% of plate appearances in the minors), hit for a high average (.293 last season) and stymie an opponents' running game (catching more than 50% of would-be basestealers last season). Powell is in major league camp right now, but the A's are being very cautious with his recovery, limiting his bullpen sessions. He was added to the 40-man roster over the winter, however, indicating that the team has faith that he is part of the organization's future plans. At this point, Powell needs to be considered solely as a part-time catcher due to his injury history, which is okay because the A's are lucky to have Suzuki ahead of him on the depth chart. But even as a part time player, Powell will be a very valuable asset to the A's at the major league level if he can find a way to stay healthy long-term.

Middle Infield - Cliff Pennington

Do I think that Cliff Pennington will have a "break out" season in 2008 and establish himself as a long-term asset to the organization? No. But do I think Cliff is better than his stats might indicate? Yes. To begin with, Cliff does exactly three things well that are very valuable for middle infielders at any level:

1) He plays stellar defense: Dan Fox of Baseball Prospectus recently ran some defensive metric numbers using play-by-play data and in his study, he found that Cliff Pennington ranked in the top-100 of all minor league infielders in terms of Simple Fielding Runs, or runs saved.  While we all know that defensive metrics are very difficult to perfect even at the major league level, let alone the minors with less information available, Fox's study profiled over 10,000 minor league players and even if you were to take the system with a lot of skepticism, it's not hard to surmise without a reasonable doubt that Cliff is a really good defender at both second and short.

2) He is a quick, efficient and smart base runner: Over his 2.5 years in the A's organization, Pennington has averaged about 16 stolen bases per season and stole them with an 82% success rate, even while battling leg injuries the past few seasons. Cliff also showcased his speed at the AFL this off-season, swiping 9 bases in 9 chances in 23 games. So Cliff's speed is an net asset to any team that he's been on.

3) He controls the strike zone: At Double-A last season, Cliff actually walked more times than he struck out (38BB's to 35K's in 271 plate appearances) and got pretty close to doing the same thing at High-A Stockton (43 BB's to 54 K's). Over the course of the season, Cliff posted walk rates of about 5% higher than league average in the California League (13.4% to Cliff for 8.8% leaguewide) and about 4% higher than league-average in the Texas League (12.1% for Cliff, 8.6% for the rest of the league).  That might not sound like a big difference, but it makes a big difference to Cliff's teams. He accumulated 81 walks between Stockton and Midland last season. If he had been merely league average at taking walks at both places, he would have collected only 48 walks all season, resulting in more than 30 less scoring opportunities for his team(s). That's a pretty big difference.

So just considering these three things, what the A's have in Cliff is a defensively solid middle-infielder that can take a walk and take a base once he gets on. Sounds better than Crosby already! So, considering these strengths, what weakness(es) have been Cliff's downfall as a prospect? Oh yeah, he can't hit!

First off, Cliff is never going to be a power hitter. He did hit 8 homers last season, which is decent for a middle infielder, but he only slugged in the high-.300s combined, giving him a season combined OPS of .713. That's not very promising, especially from a 23-year old in mid-level farm leagues. But is Cliff really that bad of a hitter? I am inclined to think no...

Cliff's combined BABIP last season was .291 and in 2006 it was .243! Those marks would be very unlucky even at the major league level, let alone the minors where pitchers allow more balls in play and defenses are much more porous. Cliff's line-drive percentage was decent at 16% and his ground ball rate of about 39% wasn't damning, so that low BABIP has to be considered somewhat unlucky and bound for a rebound of some kind this season. Even a slight-uptick in that BABIP would do Cliff a lot of good, considering his contact-oriented plate approach and above-average speed.

So if Cliff can find a few more holes in the defense and maybe up his line-drive percentage by a couple points, look for him to at least approach an .800 OPS, which, when combined with his solid defensive and baserunning skills, should be enough to get Cliff back into consideration as a legit prospect.

Corner Infield - ?

The A's page over at Scout.com thinks that Christian Vitters is a good comeback candidate, judging by his terrible 2007 season. While I agree that Vitters is bound for a comeback, I just don't think he's that good of a player. As a 22-year old in the Low-A Midwest League last season, Vitters OPS-ed a paltry .640, which, sadly, was just 38 points lower than his 2006 debut in the A's organization.  He was also moved from shortstop (which he played in college but was ill-suited to play in the pros) to third, where offensive production is even more important. Christian was a good college hitter, but I think he might just have a good metal-bat swing that hasn't translated at all to wood bats. Vitters really has nowhere to go but up, so he WILL probably rebound a bit this season, but not enough to really get people noticing.

Jeff Baisley had a down year last season after blasting 22 homers and winning MVP honors in 2006 for the Kane County Cougars...but a regression to more normal numbers was forthcoming for Jeff in 2007 as he finally caught up to a league more in-line with his age. After OPS-ing .902 in 2006 for Kane County as a 23-year old, Jeff slipped all the way to .716 with Midland last season, halving his homerun total of two seasons ago, with 11. Baisley will likely be spending the entirety of this season in AAA and I'd predict that he'd OPS anywhere from .770 to .820 over the full year with about 15 homers....which would definitely qualify Jeff as a "comeback player" and might get him a major league call up (especially if Chavez stays injured) but won't make him a long-term keeper either

Corner Outfield - Danny Putnam

There isn't a prospect in the A's organization who endured more of a rollercoaster ride than Putnam last season. He started the season at Midland where he absolutely tore the cover off the ball by OPS-ing 1.001 in about 52 at-bats. When the injury bug hit the big league team, Putnam was recalled to the majors for about a dozen games, where he hit a homerun and drove in a couple runs but generally struggled with the bat, while showing some decent skills in the outfield. Putnam was soon optioned back to Sacramento, where all of the bad luck from being a 2008 Oakland Athletic caught up to him, as he was struck by a pitch and sidelined for the next six weeks with a broken hand.

When he finally recovered, Danny was sent all the way back to the Rookie-League team and Stockton Ports for rehab stints. He eventually re-joined the Rivercats for their playoff run, and even though he was obviously still bothered by his injury, he was able to blast a couple homers in a pivotal playoff game to help the Cats advance to the PCL championship series (which they eventually won). After the season, Putnam was removed from the 40-man roster in lieu of Emil Brown, passed through waivers and re-assigned back to the Rivercats when he cleared them. Whew! Whiplash right there...

 When fully healthy, Putnam has shown that he can hit: in his only un-interrupted full minor league season at Stockton in 2005, Danny hit 15 homers, drove-in an organization-leading 100 runs and OPS-ed a healthy .867. Even last season, while his aggregate, full-season numbers were unimpressive, he had spurts where he hit really well, especially when healthy early in the season at Midland and in the PCL playoffs at the tail end. Additionally, while his bat struggled at the major league level, Danny proved that he could handle all three outfield positions, albeit in small sample sizes.

Throughout his career, Danny has shown above-average line-drive rates (when healthy) and good plate discipline even when struggling and decent, but not overwhelming, power at all levels. His power surge in Stockton in '05 was likely aided by a favorable home park and league, but the PCL is probably even more favorable to hitters than the Cal League, so another 15+ homer season for Putnam is definitely attainable. If Danny stays off the 40-man roster all season, he will be eligible for the Rule V draft next off-season, which should keep him motivated in Sacramento even though he's low on the organizational totem pole. If Danny stays healthy most of this season, there is no question that he'll put up good numbers, and at age 25, with major league experience and some defensive versatility, he should garner some Rule V interest...and even if he's not taken, he'll probably be a nice insurance policy at Sacramento for the next year or so.

Centerfield - Jermaine Mitchell

I took it as a given that Jermaine Mitchell would come back down to Earth a bit in 2007 after posting an absurdly high BABIP (.435) in a small sample size at short season Vancouver in 2006 on his way to posting a .957 OPS in his debut in the A's organization. Mitchell's numbers did deflate a bit last season, as he came all the way back down to an .803 OPS for Kane County. While Mitchell still got quite lucky in the balls-in-play department (.377) it was normal enough for the low-minors to come to the conclusion that Mitchell is probably just a pretty good gap hitter and not JUST lucky. Jermaine also improved his walk rate by about 2% over his 2006 numbers, which is a good sign for a top of the order type hitter like Jermaine. On the down side, Jermaine struck out way too much (115K's) and saw his slugging percentage decrease by almost 100 points.

I predict that Jermaine's power numbers will come back up next season as he will, presumably, be moving into the hitter-friendly California League and most especially because he will play his home games at Stockton's Banner Island Ballpark, with a short right-field porch that is very kind to left-handed hitters. While Jermaine is not a dead-pull hitter by any means, he still pulls a lot of balls into the right-center alley that should start clearing the fences at Banner Island.

Jermaine's tools have never been in question (especially his speed) and he's emerged as a legit professional center fielder with good range and a decent arm. Look for him to post numbers next season reminiscent of Danny Putnam's 2005 season in Stockton: .307/.388/.479/.867 with double digit homeruns and close to 30 steals, which should cement Mitchell as a strong candidate for the mantle of "Centerfielder of the Future".

Starting Pitcher - Kyle Christensen

There is a myriad of potential comeback players in the starting pitching ranks from top to bottom in the A's organization. But I'm picking Christensen here because although he might not be a true "comeback candidate" in the traditional sense, I think he has as great a chance as any pitcher in the organization to make great strides in overcoming his weaknesses and breaking out this season and making his way onto prospect lists.

Christensen was drafted out of Millikan High School in Long Beach as a 17-year old back in 2006. He struggled mightily in his first exposure to professional ball with the Rookie League A's, walking almost twice as many guys as he struck out (14:9 ratio) while developing an arm injury that forced the A's to shut him down after only 11 innings pitched. He came back strong last season for the Rookie League team, throwing 66 innings, with a 4.36 ERA, a 9.68 K/9 rate and a nearly 3-to-1 strikeout to walk ratio (71:25).

While the stats for Christensen are not overwhelming, his performance is very impressive considering his age. He was a very young high school senior when drafted by the A's and even though he missed most of 2006 due to his injury and had to repeat at the Rookie League last season, he is still well ahead of the curve age-wise. He'll be 19 all season in 2008.

As a pitcher, Kyle reminds me of Trevor Cahiil in a way. He's got a really projectable starting pitcher's body at 6'3, 225 and he flashes a high 80's fastball, slurvy curveball and straight changeup. He keeps the ball in the park and induces his fair share of groundballs. Kyle's arm is fresh and given his size, many observers think that he'll add a few MPH's to his fastball as he matures. Like Cahill last season Kyle should start 2008 in Kane County and stay there all year if he's doing alright. I would not be surprised if his stats next season end up looking like Trevor's, which would definitely get people noticing the kid.

Relief Pitcher - Scott Mitchinson

What? Who? Those are the same questions I asked myself until I saw Scott's name on minorleaguebaseball.com's posted Rivercats roster. Sure enough, Mitchinson was one of a handful of mostly forgettable guys drafted by the A's this off-season in the AAA portion of the Rule V draft. Mitchinson comes to the A's from Perth, Australia by way of the Phillies organization.

Scott's got some serious injury history, having missed the second half of 2006 and the first half of 2007 with arm injuries. He came back to throw about 67 innings last season split between Philly's Rookie League, Low-A and A-Ball level teams, compiling some nice stats: 3.75 ERA, 10.22 combined K/9, 1.20 combined WHiP and a .217 Batting-Average Against.

Scott's a 23-year old, command-oriented, tall, righty. He's got a fringe fastball, curveball and changeup that he mixes fairly well. He's been a starter his whole career, but since he's got established injury and durability issues (never having topped 73 innings pitched in any of his four seasons) many observers believe he's a better bet for the bullpen long-term. I tend to agree with those observers and see Mitchinson as a potential Duchscherer-esque set-up man.

I'm not sure what the exact roster rules are regarding AAA-Rule V picks, but I believe that any player picked in the AAA-portion has to remain at AAA for the whole season, or at least can't be demoted below the AAA-level. I could be wrong, but that's what the rules seem to indicate to me. This rule would complicate Mitchinson's chances of immediate success, seeing as how he has yet to pitch above the A-Ball level. Yet, the A's didn't hesitate to keep Jay Marshall on the 25-man roster all season last year when he hadn't pitched above A-ball, so I figure they'll give Mitchinson every chance to stick in Sacramento. Look for Scott  to get a chance to win a rotation spot in Sacramento and/or work out of the bullpen. If he stays healthy all season and his A-ball numbers translate well to the AAA level, Mitchinson might just get a shot at a major league spot in 2009.