Oakland A's prospect watch: Analyzing J.B. Wendelken's MLB debut

The Oakland A's called up relief pitcher J.B. Wendelken from Triple-A on Sunday, and the right-hander quickly made his MLB debut in the team's game against the Baltimore Orioles. The 23-year-old is the third Oakland player to make his big league debut this season, after righty reliever Andrew Triggs (video) and lefty starter Sean Manaea (report). Wendelken was ranked as the A's No. 22 prospect on our preseason Community Prospect List, so let's take a closer look at his first outing.

The final line wasn't pretty: 1⅓ innings, 4 runs, 2 Ks, 1 BB, 1 HR, 4 hits, on 42 pitches (24 strikes). Wendelken primarily utilized a fastball at 91-92 mph (topped out 93) and a changeup at 81-83, but he did mix in one curveball at 75. The change is his signature pitch and could be good enough to allow him to succeed with just the two-pitch arsenal, as evidenced by his 20 strikeouts in 11 innings at Triple-A Nashville this season.

Wendelken's outing wasn't great overall, but it also wasn't all bad. His first inning was excellent, as he needed only 13 pitches to breeze through with a hit and a strikeout. Had his day ended there, we'd be talking about a wonderful debut performance, and it's worth noting that only twice in 10 appearances did the Sounds ask him to record more than three outs (and not since April 10). But his entire purpose in Oakland today was to help save the rest of the A's beleaguered bullpen, so he was sent out for a second inning and that was when things took a turn for the worse.

His second frame (the bottom of the 8th) went sour right from the get-go. A single, a walk, and a single loaded the bases, and budding superstar Manny Machado followed with a grand slam. Welcome to the Show, meat! On the bright side, Wendelken got to finish on a high note by fanning $161 million slugger Chris Davis.

Let's go deeper. Batter-by-batter!

7th inning: Great!

1. Adam Jones: Single

The first pitch of Wendelken's career was an inside fastball at 92mph. Most batters probably take it for Ball 1, but not the free-swinging Jones. Instead he brought his hands in enough to pull a sharp single through the left side. It wasn't a great pitch, but there's no reason to give Jones a strike on the first offering and there's nothing you can do about it when he manages to turn that one into a hit.

2. Mark Trumbo: Popout

Wendelken fell behind 3-1 to Trumbo, on the following sequence: missed up/in with a fastball (92); dropped in a nice change (81) for a swinging strike; missed inside with a fastball (92); nearly got another whiff on a change (82) that broke out of the zone, but Trumbo just laid off. On the fifth pitch, Wendelken threw another change (82) toward the outside corner, and Trumbo skied it over the infield for the first out. Nice job by Wendelken to stick with his "out" pitch even on a three-ball count, as it looked great all three times he threw it.

3. Matt Wieters: Strikeout (swinging)

Wieters chased a high fastball (92) on the first pitch, and then fouled off another one (92) that was around the outside corner. Wendelken was finally ahead in the count, and he wasted no time turning to his bread-and-butter. The first change (83) broke too early and bounced in front of the plate, but the next one (81) was perfect. Wieters swung but the ball broke just below his bat, and J.B. had his first K. The following GIF is from the slow-mo instant replay (link to video):

That's some really nice break, both down and riding away from the lefty hitter.

4. Pedro Alvarez: Groundout

This time, against another lefty hitter, Wendelken didn't even bother with his fastball. He used a pair of changes to get a pair of swinging strikes from Alvarez; the first broke low/away (82), while the other hung up a bit (82). One more, which broke perfectly toward the low/outside corner (83), got Alvarez to tap a harmless grounder into the shift on the right side, for a 4-3 putout.

After this first inning, it's quite apparent that Wendelken's game revolves around his change. It's quite a weapon against lefty hitters, and they will surely see a steady diet of it. However, what we didn't see -- and what we will continue to not see in the next inning -- is a similar weapon that he can rely on against righties.

8th inning: Disaster!

5. Jonathan Schoop: Single

Wendelken started off the next inning by throwing his only curveball of the day (75). It had good break but the location was way off, as it missed way inside and made Schoop jump away from the plate. A fastball (92) just nicked the bottom of the zone for Strike 1, but the next fastball (92) hung up and got lined to right for a clean single.

6. Ryan Flaherty: Walk

Flaherty is one of the worst hitters on the team and you really shouldn't walk him, so this was a disappointing at-bat.

The first-pitch fastball (93) caught the up/outside corner for a strike, but the next fastball missed down/in to make it 1-1. After a pickoff throw to first, Wendelken finally went to the change (81) against the lefty but it broke way down and Flaherty didn't chase. Another fastball (91) induced a foul, but the 2-2 change (81) missed way up to bring the count full. One more change (80) didn't do the trick, as it started too low and never fooled Flaherty into chasing the break, and the guy with a career OPS of .646 had himself a free base. The difference between this at-bat and the ones in the previous inning was that the changeups were significantly worse and did nothing to fool the lefty batter.

7. Joey Rickard: Single

I want to say something snarky like "I've never heard of this guy" but I'm also the one writing over a thousand words about the debut of a middle reliever, so ... Rickard is a Rule 5 pick who has captured the leadoff spot for the Orioles.

Anyway, this was another long at-bat. An inside fastball (92) induced a weak half-swing; another fastball (92) missed way up/in; another (91) missed high; and a change (81) caught the inside corner to make it 2-2. The subsequent fastball (92) hung up/in and Rickard smashed it foul into the upper deck, and then a change (82) missed low and Rickard held up for a full count. Finally, a fastball (91) hung up over the plate and was lined into left for another single to load the bases.

8. Manny Machado: Grand slam :-(

Once again, a long at-bat. The Baltimore hitters really made Wendelken work in this frame.

A change (81) broke inside for a ball; another change (81) broke perfectly and got Machado to chase for a strike; he just missed a fastball (92) down the middle, fouling it straight back; a change ran way in for Ball 2; and a fastball (92) missed low. With the count full, and nowhere to put Machado with the bases loaded, Wendelken had no choice but to go after him. He did not, however, have to cook up the biggest meatball in the state of Maryland and serve it on a platter like this (link to video):

As you can see, the catcher was set up low and Wendelken just missed his spot by, oh, two feet or so. Machado hit 35 homers last year in his age-22 campaign and now leads all of baseball with a 1.094 OPS this season, so on one hand you can't be that bummed about getting beaten by him but on the other hand don't miss your spot by two feet against him.

9. Chris Davis: Strikeout (looking)

The five at-bats in this inning, by number of pitches: 3, 6, 7, 6, 7. Wendelken missed his spots a few times, but I think this was more a product of the Orioles being incredibly selective than Wendelken being wild. Which is odd, since the Orioles tend to be one of the more aggressive teams at the plate.

Davis watched a first-pitch change (83) in the dirt for Ball 1; another one (81) just low on the outside corner; a fastball at the knees (92) for a called strike; a fastball (91) on the outside corner for another strike; another (92) on the outside corner that was fouled away; and a change that only made it about 50 feet to run another full count. Wendelken mustered up one more perfect change that sliced through the zone as it broke, freezing Davis for Strike 3.

Final Review

All told, I give mixed reviews to Wendelken's maiden voyage in the bigs. He had one good inning and one bad inning, and the bad inning came while he was being asked to set a season-high in pitches thrown. He looked sharp against lefties, but powerless against righties. His fastball didn't appear to have much life and only seems to exist in order to contrast with his change. His change looked great when he located it, but he did overthrow it a few times -- not out of the ordinary for a pitcher with some debut jitters.

Thanks to the grand slam, he now has an unsightly 27.00 ERA to open his MLB career. However, if that's all you look at then you will be selling his performance short. He struck out a pair of All-Star sluggers and got beat on a mistake pitch by the current best hitter in baseball. It could have been worse, and I'll be interested to see how he looks his next time out.