For years, the A’s have been excited about the impact that could be on the horizon with the talented pitching prospects in the organization. That time seems to be quickly approaching.

A.J. Puk -- Oakland’s No. 2 prospect per MLB Pipeline -- made a rehab appearance for Triple-A Las Vegas on Tuesday night. The left-hander worked a scoreless inning of relief on 20 pitches, allowing just two hits while striking out three batters.

After impressing in his lone appearance of the season with Oakland on April 5, an outing in which he held the Dodgers scoreless over 3 1/3 innings, Puk landed on the injured list shortly after with a biceps strain. He’s expected to get at least two more outings with Las Vegas, with a return to Oakland dependent on how he feels after each appearance.

“When you’ve got somebody dealing with injuries, you always want to see how they feel the next day,” A’s pitching coach Scott Emerson said before Wednesday’s game against the Red Sox. “A.J. has a couple more outings scheduled, and we’re going to take it one day at a time with him. Get his feedback after every [outing], and then we’ll go from there.”

Puk’s positive step forward on Tuesday was followed up with more exciting developments on the pitching prospect front on Wednesday with James Kaprielian, Oakland’s No. 10 prospect, taking the mound at Fenway Park for his first Major League start.

“It’s an exciting time for the organization,” Emerson said. “James feels very confident in his abilities. He’s a confident kid. Now it’s just go out there, compete and enjoy the moment.”

Pinder homers in rehab appearance
Chad Pinder (left knee sprain) homered as part of a 3-for-4 night on Tuesday in what was his second rehab game with Triple-A Las Vegas. Expected to get another game in on Wednesday, the super-utility player could rejoin the A’s as early as Friday night in Minnesota for the start of a three-game series against the Twins.