Inside Pitch: A’s co-aces a perfect picture of plus-minus

Entering the 2018 MLB season, Oakland’s greatest question lied in the rotation.

There was definitely promise, though even that took a hit in the form of three key injuries suffered during Spring Training, but there were several resounding questions.

Limited in both experience and sustained success, Athletics starters were tasked with keeping their young budding offense in games in order to hand a rebuilt bullpen late leads. Two-and-a-half weeks into the season, they have largely failed in doing so, toting the game’s worst batting average against (.277) and sixth-worst starter ERA (4.79).

But positives still linger for the A’s (6-10). And both sides of the coin are no more perfectly personified than by the club’s co-aces.

On one end of the spectrum, Opening Day starter Kendall Graveman, whose struggles have stupified the A’s scrambling coaching staff, has not been able to control his sink-less sinker resulting in four of the worst starts in his major league career.

On the other end, Sean Manaea (2-2, 1.63 ERA, 0.72 WHIP) carries the league’s eighth-best ERA among hurlers with 20 or more innings pitched, along with the sixth-best WHIP and second-best WAR (1.2).

The only thing Manaea has thus far been unable to do is win — being saddled with losses in a pair of starts in which he allowed and combined three runs in 12-2/3 innings. That is because he has received an average of just 2.25 runs of support per game. The runs will come, as long as he continues to average seven innings of one-run ball.

As dominant as Manaea has been, Graveman (0-3, 9.87 ERA, 2.02 WHIP) has been that bad.

Graveman is in the midst of his worst stretch in the major leagues. Just once, in his 76 big league appearances prior to 2018, had Graveman surrendered four or more runs in four consecutive starts (April 25-May 14, 2017). He had never, in his 71 previous starts, recorded fewer than 16 outs in four straight — in fact, his worst run of such short-lived outings had been just twice consecutively, which he had done four times entering his age-27 season. Never had he served up homers in four straight appearances.

He has done all of those things in each of his first four starts.

The problem is well documented: he is a sinker-baller who has lost his sink.

Small sample size, sure, but his 1.43 ground ball-to-fly ball ratio is the worst season mark of his major league career (career 1.81, according to Fangraphs). With his strikeout rate also down, Graveman, for the first time in his career, faces a ground-ball percentage is below 50 (career 49.3 percent).

So, why? As conventional wisdom says, with a jump in velocity comes a drop in movement.

Graveman’s velocities are up across the board. Slider (81.1 mph), cutter (90.2), changeup (86.5), all of his weapons are coming at a higher velocity than his career averages (78.8, 88.1, 85.6) by more than one mph each. And his sinker this year has averaged 93.7 mph, bringing his career average up to 92.5.

Manager Bob Melvin told Susan Slusser of the SF Chronicle:

“He’s just overthrowing some. He’s got to figure it out; he’s important to us. He will.”

In an attempt to stymie the velocity bump, Melvin and pitching coach Scott Emerson had the right-hander throw more than usual in his bullpen day between starts No. 3 and 4 hoping to fatigue his arm. That didn’t work.

Graveman lasted just four innings in Seattle, giving up five runs on eight hits including a major league-leading sixth home run.

The Oakland brass is running out of options. And while on the surface, everyone, including Graveman, seems confident that the hurler will find his sink, Melvin can’t afford to continue throwing him out there to get hammered for four innings before asking his already overworked bullpen — which has worked 57 innings through the first 16 games (3.6 per game) — to eat five innings and keep the offense within reach.

Trevor Cahill, who is 0-1 with a 3.72 ERA and 1.138 WHIP in two starts with Triple-A Nashville this season, is back in Oakland and will return to the Coliseum mound Tuesday. Graveman has minor league options available, should that route be forced upon the A’s. Chris Bassitt, working his way back from a 2016 Tommy John surgery, has also been effective in Nashville — four hits, two walks and 11 strikeouts in eight innings (two games) of scoreless relief.

So the option is there. And maybe a trip to Tennessee is just the medicine for the Alabama-born Graveman, who is facing the demand that comes with the title “ace” for the first time in his five-year career.

Perhaps allowing him to step back, settle down and return to the dominant form he has shown so many times with the A’s will get Graveman’s sinker back to sinking.

As promising as the offense appears to be, and as potent as the ‘pen can be, the A’s hopes of ascending from the American League West cellar lies with the rotation. That aspiration will require continued success from Manaea and a return to form of Graveman.

Kalama Hines is SFBay’s sports director and Oakland Athletics beat writer. Follow @SFBay and @HineSight_2020 on Twitter and at SFBay.ca for full coverage of A’s baseball.