The A’s bullpen has begun to click during the team’s 11-game winning streak, and right in the middle of that renaissance is the unit’s elder statesman.

Yusmeiro Petit, 36, remains one of Oakland’s most reliable bullpen options, serving to bridge the middle innings to the final frames. In 10 2/3 innings this season, Petit has only allowed two earned runs (1.69 ERA) and two walks. The veteran showed he’s still capable in a multi-inning role as well, tossing two scoreless frames in the A’s thrilling 13-12 win over the Twins.

Command has been, and will continue to be, the name of Petit’s game. This season, Petit’s fastball has clocked in with an average velocity of 86.9 mph, the continuation of a downwards trend since he signed with Oakland. Yet, even in a league that has seen velocity numbers gradually increase, Petit is still finding ways to get batters out.

Along with the low walk rate, Petit’s command has helped him generate weak contact. Thus far, Petit ranks in the 75th percentile of xwOBA (Expected Weighted on Base Average) and xERA (Expected ERA). Petit’s great command certainly helps, but he offered an additional hypothesis -- one that speaks to his role in the ecosystem of Oakland’s bullpen.

Every time Petit takes the mound, he is likely following someone who throws harder than him. The same applies when he departs -- the reliever who comes in after Petit will, more often than not, throw harder than him.

Petit says this effect is two-fold. If Petit comes in after Jesus Luzardo or Frankie Montas, his slower velocity requires an adjustment in perception. When Petit departs, opposing hitters will have to readjust to a higher speed. That, in turn, can make the subsequent reliever’s velocity feel much faster.

“That’s the combination I have for the other bullpen guys,” Petit said.

"He’s a pretty smart guy. There’s probably something to that,” said manager Bob Melvin.

Take, for example, Petit’s appearance against the Tigers on April 16. Petit came on in relief for Montas, whose average sinker that day was 95.6 mph. In Petit’s one scoreless inning, his fastball averaged just 86.7 mph. After Petit came Diekman, who threw a scoreless frame of his own with an average fastball velocity of 93.4 mph.

Petit’s theory hasn't undergone the rigors of the scientific method, but the results are hard to argue. Since joining the A’s in 2018, Petit has logged 208.1 innings, the most by any reliever during that span.

“He just does things a little bit differently,” Melvin said. “Maybe when somebody comes in and throws harder behind him, maybe looks harder than that. I wouldn’t disagree with that.”

Injury updates

Melvin provided injury updates Friday afternoon on RHP Mike Fiers, LHP A.J. Puk and outfielder Chad Pinder.

Fiers (lumbar strain) has been cleared to pitch, but the A’s are still trying to figure out what roster moves to make, as well as the most appropriate day for his debut. When asked if Fiers could start on Sunday, Melvin said he was unsure and that the team is keeping its options open.

Puk (left biceps strain) is not throwing yet and was shut down for several days, but Melvin said that the southpaw will start playing catch again on either Friday or Saturday.

Pinder (left knee sprain) started his running progression on Wednesday, but Melvin said he likely won’t begin baseball activities until the A’s begin their next homestand, which begins April 30.