Oakland A’s acquire reliever Jake Diekman from Royals

The Oakland A’s made another trade with the Royals on Saturday, acquiring left-handed reliever Jake Diekman, first reported by insider Jeff Passan. The team later officially announced the deal.

In exchange, the A’s are sending two minor league prospects to Kansas City, RHP Ismael Aquino and OF Dairon Blanco. Neither are currently listed in the team’s Top 30 prospects on MLB Pipeline, though Blanco cracked the bottom of our preseason Community Prospect List at No. 27.

Oakland had an open spot on their 40-man roster, so no corresponding move will be necessary to make room, though of course someone will have to go from the 25-man squad.

The addition of Diekman (pronounced DEEK-man) gives the A’s another powerful presence in their bullpen, as well as another lefty arm that they desperately need. His strikeout rate is one of the highest in the sport, at just over one-third of all the batters he faces and more than 13 per nine innings. He does issue a lot of walks, but also keeps the hits low and avoids homers, the latter of which is particularly impressive in today’s dinger-happy environment.

Diekman, 2019: 4.75 ERA, 41⅔ ip, 63 Ks, 23 BB, 3 HR, 3.37 FIP

On top of those stats, he’s converted 18-of-20 save/hold chances this year, though he’s also picked up five more losses in tie games. Over the last four seasons he’s converted 73-of-77 save/hold chances, which is an incredible 95% success rate (7 saves, 66 holds, 4 blown). He does not have significant platoon splits, either for this year or his career overall, with hitters on both sides struggling to do much against him other than walk. Statcast rates him comfortably better than average, with a .292 xwOBA (MLB reliever average is .316).

For his career, dating back to 2012 (in 353⅔ innings, mostly with Phillies and Rangers), Diekman’s numbers are similar to what he’s done in 2019 but with two huge exceptions. His lifetime ERA is 3.87, nearly a run lower than this year, even though he’s currently striking out two more batters per nine innings than his previous norm. Otherwise, his rates of walks, hits, and homers, as well as his FIP, are nearly identical to his career marks. The spike in strikeouts is spurred by an enormous 17.4% swinging-strike rate, which is several points higher than his previous high, and top-10 among all MLB pitchers with at least 30 innings this year.

Diekman’s arsenal relies mostly on two pitches, both of which he’s using over 40% of the time this season. His four-seam fastball averages over 95 mph and can dial up toward 99, the third-highest velocity among all qualified lefty relievers in the majors, and his slider sits in the low/mid-80s. He’s using his slider more than ever this summer, turning to it for nearly half of his total offerings, up from a quarter to a third in previous years. Click here for quick video of both pitches. Earlier in his career he also threw a sinker, but since 2018 Statcast has mostly identified his fastball as a four-seamer instead.

In terms of contract and team control, Diekman is earning $2.25 million this season, and has a mutual option for 2020 at $5.75 million (with a $500K buyout).

As for the prospects going the other way, neither has high stock but both have at least some intrigue. Blanco’s carrying tool is 80-grade speed, the highest possible grade on the scouting scale, and he’s used it to steal 49 bases in 58 tries over the last two years since arriving in U.S. pro ball. However, the 26-year-old is still only in Double-A, where he has fairly high rates of strikeouts and swinging strikes, so he’s got a long way to go and is already old for a prospect.

Meanwhile, Aquino is a 20-year-old who has mostly pitched in Rookie Ball in his young pro career. He hasn’t played enough, nor at a high enough level, for his stats to be worth analyzing. Last winter, FanGraphs included him in the “exciting longshot arms” section of their A’s prospect list, with the note that he “sits 93-96 [mph], but it’s a relief-only delivery.” For more info on both outgoing prospects, check out Melissa Lockard’s writeup at The Athletic.

This is the second trade the A’s have made this month, both with the Royals. Oakland previously acquired starter Homer Bailey back on July 14, for another speedster prospect in Kevin Merrell. However, they might not be done yet, as noted by Ken Rosenthal of The Athletic:

The A’s pen currently includes Hendriks, Soria, Petit, Buchter, Treinen, Trivino, Schlitter, and Wang, though presumably one of those arms will go to make room for Diekman. Buchter and Wang are the lefties in that incumbent group.

Hot takes

Love it. This is finally the southpaw late-inning reliever that the A’s have needed for a looong time. Ryan Buchter has done a fine job for the last two seasons, but they needed another lefty to pair with him even before Buchter went through some struggles this year. In an odd coincidence, Buchter was also acquired in a trade from the Royals, two winters ago.

Diekman has seemed like a logical trade target for the A’s since last summer, and indeed he was dealt in 2018 but not to Oakland. Now he’s finally here. He’s a good lefty with a lot of upside, but he isn’t a big-name closer or setup man who would cost a premium price.

In fact, it feels like the A’s got a serious bargain here. Blanco and Aquino have their strengths but are not highly rated prospects, and our friends at Baseball Trade Values have this deal being lopsided in Oakland’s favor. Whether you believe that valuation or feel it was closer to an even swap, the A’s still didn’t even make a mildly perceptible dent in their farm system with this deal. Much like the Bailey trade, this feels like nabbing a pitching upgrade at a crucial moment for basically free.

And to be clear, this is an upgrade. Buchter has settled down from his early-season slump to lower his ERA to 3.18, but his 4.88 FIP is still the worst of his career and represents a red flag moving forward. Furthermore, every single one of his key rates is worse than Diekman’s, including Ks, BB, HR, hits, etc. Buchter has also blown four save/hold chances in 2019, which matches Diekman’s total from the last four years combined. Wang has a similar story, with an impressive 2.66 ERA backed by a worrisome 5.25 FIP, thanks in part to an utter lack of strikeouts.

On the other hand, the advanced predictive metrics love Diekman, though his ERA has stayed high for two seasons now. But he’s posted low ERAs before, and the smart bet is that he can do so again as long as he keeps striking out the world and allowing little to no hard contact.

Welcome to Oakland, Jake! We’ve been expecting you.