The A’s were destined for a bullpen game. Sean Manaea was chased from Thursday’s outing against the Red Sox after two-plus innings, and a procession of Oakland relievers appeared imminent.

Enter Deolis Guerra.

The right-hander pitched three scoreless innings following Manaea’s brief start during Oakland's 8-1 loss at Fenway Park, not just keeping the A's in the game but preserving the bullpen. For Guerra, it was just the latest example of the value he provides.

“He’s saved us a bunch of times,” manager Bob Melvin said.

Guerra, who owns a 2.65 ERA across 17 relief innings entering Friday night's game against the Twins, has been a revelation for the A’s, especially given the injuries that the pitching staff has endured.

Similar to fellow Venezuelan Yusmeiro Petit, Guerra has often been used in long relief. Of his 11 outings, five have stretched multiple frames. When Jesús Luzardo pitched only 2 2/3 innings against the Diamondbacks on April 13, Guerra pitched three innings of scoreless ball, serving as a bridge to the back end of the bullpen.

“Maybe not even conditioned to be length, but economical in his pitches, gets you outs,” Melvin said.

Along with his ability to eat up innings, Guerra has been effective because of his reverse splits, being tougher against left-handers than right-handers.

In Guerra's career, lefties have a batting average of .205 against him, while righties have an average of .304. That difference has been even more stark this season, with lefties hitting just .043 and righties hitting .216. So what has fueled that success?

“I think it’s all because of the changeup,” Guerra said.

Guerra describes the changeup as his “go-to” pitch, the origins of which date back to his childhood. When Guerra played Little League in Venezuela, there was a rule regarding pitch repertoire: no breaking pitches.

With no sliders, curveballs and the like at his disposal, Guerra was limited to fastballs and changeups. Guerra didn’t want a one-pitch repertoire, so with the help of his coaches, he began learning how to throw an effective change-piece. One piece of advice in particular stuck with Guerra: “Let the fingers work.”

The pitch has certainly worked wonders for Guerra in his first season with Oakland. This year, opponents have mustered only three hits, all singles, in 21 at-bats (.143) against Guerra’s changeup. Lefties have fared even worse, as Guerra's changeup has limited them to just one hit in nine at-bats (.111).

“I’m always sinker-changeup to the lefties,” Guerra said. “Trying to always work that outside corner up and down. I think the changeup gets them off balance a lot of times.”

Pinder reinstated
Chad Pinder has been reinstated by the A’s and will be available off the bench, the club announced Friday.

Vimael Machín was optioned to Triple-A Las Vegas to make room for Pinder. Machin will remain on Oakland’s current road trip as part of the taxi squad.

Pinder began the season with electrifying play on both sides of the ball, but he has been limited to just four games after suffering a left knee sprain.

Melvin envisions Pinder playing “everywhere" in the field, as well as being in lineups against left-handed pitching.

“That’s kind of what he does for us, is play different positions,” Melvin said. “I don’t see that changing a lot. Maybe sometimes in the infield a little bit more, but we’ll see how it goes.”

Given the emergence of outfielder Seth Brown in recent weeks, it will be worth monitoring how Oakland divides playing time among its outfielders.