Manaea’s Loss Further Thins Oakland’s Decimated Rotation

Does anybody have a phone number for Vida Blue or Dave Stewart? Maybe Tim Hudson? The A’s could use another starter for their playoff push, because on Tuesday, they got the definitive news on Sean Manaea, and it was quite bad. The 26-year-old lefty hasn’t pitched since August 24 due to what was initially diagnosed as shoulder impingement and then revised to tendinitis in his rotator cuff. Not only will he not return this season, as initially hoped, but he’ll undergo arthroscopic shoulder surgery next week, and is expected to be sidelined through 2019.

The timeline isn’t unlike that of a late-season Tommy John surgery candidate such as the White Sox’ Michael Kopech, but returns from shoulder surgery are far less predictable than those from ulnar collateral ligament repair. In Manaea’s case, the exact diagnosis is unclear, at least as far as the general public goes; the range of possibilities could include a bone spur in his shoulder, and/or a tear in his rotator cuff, labrum, or anterior capsule — or some combination of those injuries. Manager Bob Melvin told reporters, “The specifics we’ll talk about more after the surgery, so we’ll know exactly what was repaired.”

Ouch. Say, what’s Barry Zito doing these days?

Manaea is the 10th Oakland starter to land on the disabled list (a total of 13 stints, according to the San Francisco Chronicle’s Susan Slusser) and the fifth to suffer a season-ending injury. The other four were Tommy John recipients: Jharel Cotton and A.J. Puk were cooked before the season even started, while Opening Day starter Kendall Graveman and April 1 (game four) starter Daniel Gossett combined for just 12 starts before going down. Indeed, the first cycle through the A’s rotation looks like the dwindling cast of a horror movie, with Manaea (who started the season’s second game) and Andrew Triggs (who started the fifth, and is now on a rehab assignment, recovering from a nerve irritation issue) currently sidelined. Daniel Mengden, who started the season’s third game, is the only one currently active; in late June and early July, he served a DL stint for a sprained right foot. Also out are lefty (and perennial DL denizen) Brett Anderson, who is nearing a return from ulnar nerve irritation, and righty Paul Blackburn, who’s without a timetable as he works his way back from lateral epicondylitis (tennis elbow).

Has anybody checked in on Ken Holtzman? Mike Moore? Neither would look all that out of place in a rotation that nobody could have envisioned in April, let alone predicted would be part of a playoff-bound team:

Oakland A’s Rotation Comparison, March/April vs. September
Season Opening GS ERA FIP WAR Current GS ERA FIP WAR
Kendall Graveman 7 7.60 6.22 -0.4 Mike Fiers 7 2.72 4.27 0.4
Sean Manaea 27 3.59 4.26 1.7 Liam Hendriks 3 6.32 5.33 -0.1
Daniel Gossett 5 5.18 5.95 -0.2 Edwin Jackson 14 3.26 4.65 0.6
Daniel Mengden 16 4.26 4.62 0.6 Trevor Cahill 19 3.77 3.52 1.9
Andrew Triggs 9 5.23 4.80 0.2
All statistics through September 11, with Oakland only. Pitchers listed in order of appearance.

So decimated is Oakland’s rotation stock that the team has used Hendriks as an opener three times in the past week, with Mengden (twice) and Chris Bassitt doing the heaviest lifting once he departed. The A’s have won only one of those three games, but one has to admire the resourcefulness of the Billy Beane/David Forst front office. The team is somehow an MLB-best 47-19 (.712, tied with the Red Sox) since Jackson — who went to spring training with the Nationals and opted out of his minor-league deal on June 1 — debuted on June 25, after Mengden got hurt, and 21-11 since acquiring Fiers from the Tigers in a waiver-period deal on August 6. Cahill wasn’t even signed by the team until March 19, and didn’t debut until April 17. He’s since survived trips to the DL for elbow impingement and a right Achilles strain to produce the staff’s highest WAR this side of closer Blake Treinen (3.3) and the second-highest total of innings (102.2). With Manaea tapping out at a career-high 160.2 innings, the A’s will finish without a single pitcher qualifying for the league ERA title, though it was only last fall that the Astros won a World Series without one.

Including Hendriks, the A’s have used 14 starters this year, tied with the Blue Jays for fourth in the majors behind the Rays, Angels, and Twins. Despite the turnover, the unit has been in the middle of the AL pack, ranking sixth in ERA- (100) and eighth in FIP- (106). The unit has the league’s third-lowest strikeout rate (17.6%) but also the highest ground-ball rate — and, thanks largely to a stellar infield of Matt Olson, Jed Lowrie, Marcus Semien, and Matt Chapman, they have the major’s fifth-lowest BABIP on grounders (.208). Overall, though, the makeshift rotation, which is just 10th in the AL in innings (769.2) has the lowest WAR total of any contender in either league (7.3) and ranks just 20th overall:

The A’s have thrived because they’ve built one mother of a bullpen, a unit that’s even punching far above its weight in WAR, where it ranks seventh in the majors:

As Jeff Sullivan wrote earlier this week, the A’s bullpen has been particularly brilliant in high-leverage situations, with a .204 wOBA allowed, 51 points lower than any other team this year. Their 13.4 WPA is the second-highest since 1974, as far back as our win-expectancy data currently goes and on pace to surpass the 2012 Orioles (13.5) for the record.

Back to Manaea, for whom we should pour one out before moving on. He began the 2018 season on the best roll of his career, posting a 1.03 ERA and 3.21 FIP in 43.2 innings across his first six starts, five of which saw him allow one run or fewer. The peak of that run, of course, was his April 21 no-hitter against the Red Sox, during which he struck out 10 and walked just two. Here’s the ninth inning:

For as strong as his March/April was, Manaea was dreadful in May (7.18 ERA, 5.68 FIP) and, thereafter, leveled off. He finishes his season with both the lowest ERA of his career (3.59) and the highest FIP (4.26) en route to a career-low WAR (1.7, down from last year’s 2.2).

On the one hand, Manaea posted the lowest swinging-strike and strikeout rates of his career; his 9.7% swinging-strike rate was nearly two points below his 2016-17 mark (11.6%), while his 16.5% strikeout rate was four points below what he did in his first two seasons. On the other hand, he did compensate with the league’s fifth-lowest walk rate (4.9%), and he also benefited from a league-low .247 batting average on balls in play, much of which certainly owes to the aforementioned stellar infield defense behind him. Following up a stat I noted while writing about the unlikely success of Jackson, Manaea is one of five A’s who rank among the majors’ top 15 in the largest differential between wOBA and expected wOBA:

Largest wOBA-xwOBA Differentials, 2018
Rk. Pitcher Team wOBA xwOBA Dif
1 Matt Koch D-backs .338 .413 -.075
2 Michael Wacha Cardinals .286 .360 -.074
3T Yoshihisa Hirano D-backs .257 .324 -.067
3T Daniel Mengden Athletics .308 .375 -.067
5 Edwin Jackson Athletics .295 .352 -.057
6 Sean Manaea Athletics .287 .341 -.054
7 Jake Faria Rays .325 .375 -.050
8 Blake Treinen Athletics .193 .241 -.048
9 Raisel Iglesias Reds .282 .329 -.047
10T Chad Green Yankees .274 .320 -.046
10T Miguel Castro Orioles .315 .361 -.046
12T Clay Buchholz D-backs .269 .314 -.045
12T Collin McHugh Astros .243 .288 -.045
12T Dan Straily Marlins .324 .369 -.045
15T Julio Teheran Braves .295 .338 -.043
15T Yusmeiro Petit Athletics .274 .317 -.043
15T John Gant Cardinals .271 .314 -.043
18T Mike Leake Mariners .325 .366 -.041
18T Trevor Williams Pirates .288 .329 -.041
18T Reynaldo Lopez White Sox .320 .361 -.041
SOURCE: Baseball Savant
Minimum 1,000 pitches.

At least the other guys are still standing, right?

As to how the team would piece together a postseason rotation, the answer for the Wild Card game agains the Yankees may be to bullpen the hell out of it, particularly if the game is in Yankee Stadium — which is no longer a guarantee, as the Yankees (90-55) lead the A’s (88-57) by just two games. As the San Francisco Chronicle’s John Shea wrote, “Don’t be surprised if management decides to go bullpen happy in a wild-card game, especially because it likely would follow two off days.” Shea’s logic hinged in part on the unflattering but small-sample track records of Fiers, Jackson, Cahill, and Anderson in the House That Steinbrenner Built, but one look at what the front office has done of late, adding Jeurys Familia, Shawn Kelley, and Fernando Rodney to a core that includes Treinen, Petit,and Lou Trivino, and it’s not hard to understand that Oakland’s road through October probably will include what Shea calls “a conga line of relievers.”

Which means it’s probably time to give Rollie Fingers and Darold Knowles a call.

Brooklyn-based Jay Jaffe is a senior writer for FanGraphs, the author of The Cooperstown Casebook (Thomas Dunne Books, 2017) and the creator of the JAWS (Jaffe WAR Score) metric for Hall of Fame analysis. He founded the Futility Infielder website (2001), was a columnist for Baseball Prospectus (2005-2012) and a contributing writer for Sports Illustrated (2012-2018). He has been a recurring guest on MLB Network and a member of the BBWAA since 2011, and a Hall of Fame voter since 2021. Follow him on Twitter @jay_jaffe... and BlueSky

Newest Most Voted
Inline Feedbacks
View all comments
5 years ago

Still bummed we lost the Rodney arrow… Give him back the 9th…please!

5 years ago
Reply to  Billsaints

Are you suggesting turning Treinen back into a starter, now that he has four plus pitches? Insanity? Or brilliance?

Rodney would still only be third in line to close out A’s games though…