OAKLAND -- The A’s are calling upon one of their most exciting young arms for help.

Left-hander A.J. Puk, who is rated Oakland’s No. 2 prospect by MLB Pipeline, was called up from the club’s alternate training site in Stockton, Calif., on Monday prior to the start of a three-game series against the Dodgers at the Coliseum.

To make room on the active roster, the A’s placed outfielder Chad Pinder on the 10-day injured list with a left knee sprain that was sustained in Sunday’s loss against the Astros after he made a leaping catch before crashing into the right-field wall.

Puk, 25, will work out of the bullpen, providing aid to an exhausted relief corps that worked 16 2/3 innings over the last four days against Houston. The situation was so dire that the A’s even had to call upon rookie outfielder Ka’ai Tom to pitch the ninth inning on Sunday.

Working his way back from left shoulder surgery last September, Puk produced mixed results in a Spring Training battle for the A’s final rotation spot. He posted a 5.87 ERA in three games (two starts), but he finished his Cactus League campaign on a high note by allowing just one hit with three strikeouts and no walks in four scoreless innings against the Rangers on March 27.

When Puk arrived to Oakland in August 2019 for his Major League debut, the 6-foot-7 lefty also pitched as a reliever, a role in which he finished with a 3.18 ERA in 10 appearances and dazzled with fastballs that averaged 97.1 mph and occasionally hit triple digits. In Spring Training, that fastball velocity sat around 93-94 mph, leading to Puk increasing the usage of his two-seam fastball.

It can take pitchers months or even years to regain their original velocity after undergoing shoulder surgery. Perhaps the velocity will tick up in shorter bursts out of the bullpen. Regardless, Puk didn’t seem too concerned with the numbers on the radar gun this spring.

“Even if my velocity doesn’t come back to having 98 mph in my back pocket, I’m still confident with the stuff I have,” Puk said after his final Cactus League outing. “That’s why I’m working on this two-seamer. I’ve always told myself I want to become a pitcher. Previous to these injuries, it was pretty easy to become a thrower with 98 any time I want. Now I’m working on becoming a pitcher.”

A’s manager Bob Melvin was uncertain how he might use Puk in games. In 2019, he utilized Puk as a multi-inning weapon to bridge the game to closer Liam Hendriks. After what transpired over the past four days against Houston, Melvin did not want to commit to any specific role for the left-hander.

“It just depends,” Melvin said. “You can plan all you want, and then on certain days, you only have so many guys available. We were in a little bit of a difficult position yesterday. At this point, he can go two or three innings if we need that.”

Laureano still out, Murphy returns
The A’s inched closer to full strength on offense with Monday's return of Sean Murphy. The catcher was in the starting lineup after missing the last three games with a right wrist contusion. Murphy’s presence could help what has been a rough go for the offense to start the season, particularly in clutch situations. During their four-game sweep at the hands of the Astros over the weekend, A’s hitters went 4-for-28 with runners in scoring position.

Murphy enjoyed a breakout rookie campaign last year, leading the A’s in OPS (1.062) and home runs (five) over the final month of the season as he slashed .277/.424/.638 across 16 games in September.

“Murph is a true two-way guy and a starter,” Melvin said. “Especially in a series where you’re going to need to score some runs, it’s nice to have him back.”

Ramón Laureano remained sidelined for a third straight day after jamming his left wrist in Friday’s loss to the Astros. Melvin said the center fielder is considered day to day.

“One day, you feel like you have some progress, and then the next day, maybe not,” Melvin said. “Hopefully he plays tomorrow. But I’m not certain of that.”