Due to the heavy workload placed on the A’s back-end bullpen trio of Yusmeiro Petit, Jake Diekman and Lou Trivino early in the season, manager Bob Melvin said another reliever would have to step up and help ease that burden.

Burch Smith might be that guy.

Smith is quickly ascending on Oakland's bullpen depth chart since returning from the injured list last week. In two relief appearances over that span, Smith has been perfect, working two innings each time out and retiring all 12 batters he’s faced.

Not only is Smith providing length, he’s bringing it at clutch times in games. During Wednesday’s victory over the Red Sox, he took over in the sixth with a three-run lead after rookie James Kaprielian’s high pitch count led to him lasting just five innings. Smith got through two scoreless frames with ease, serving as the bridge to the back end of the bullpen, with Trivino and Diekman closing out the win in the final two innings.

“This was big for us to get him back,” Melvin said. “Burch was a guy that we really felt like, when a starter doesn’t go too deep, he can go two innings. He’s done it a couple of times for us. It’s been big to get him back and he’s been up for the task.”

Going multiple innings is nothing new for Smith. Since joining the A’s in 2020 via trade from the Giants, the 31-year-old righty has made 10 relief appearances and pitched at least two innings in five of them. Four of those five have been scoreless; he allowed just one run in 14 1/3 innings over those contests.

So on a night like Thursday against Boston when Diekman is likely unavailable after closing out the previous two games, Melvin won’t hesitate to insert Smith into a high-leverage situation.

“He pops up into that complement, especially against righties,” Melvin said. “What Burch has done has just made us a deeper bullpen."

Pinder set to return

Chad Pinder (left knee sprain) will finish off his Minor League rehab assignment by playing one more game at Triple-A Las Vegas on Thursday. If all goes well, he’s expected to return to the A’s in their upcoming three-game series at Minnesota on either Friday or Saturday. The super-utility player has gone 3-for-8 with a homer in two games for Vegas.