After missing the start of the season due to a shoulder injury, Zack Gelof is finally back in action.

Gelof, Oakland’s No. 2 prospect, made his 2023 debut with Triple-A Las Vegas earlier this week. Entering Sunday, the infielder was 3-for-10 with a double, RBI and five walks over three games with the Aviators.

Having finished the 2022 campaign at Triple-A, the expectation is that Gelof will make his way to Oakland at some point this year as long as he stays healthy. Performance could dictate the speed of that decision, and so far, the 23-year-old has done nothing but impress.

In a limited Spring Training with the A’s due to his participation with Team Israel in the World Baseball Classic, Gelof played in 11 Cactus League games and went 8-for-25 (.320) with two doubles, an RBI and three walks.

“We saw enough to know that, for Zack, what’s left for him to do in the Minor Leagues is to go dominate a level,” A’s manager Mark Kotsay said near the end of Spring Training. “He’s aware of that, and he’s excited for his opportunity.”

Triple-A Las Vegas
Count Kotsay among those who were blown away by the recent performance of A’s No. 3 prospect Mason Miller.

Making his 2023 Triple-A debut on Friday, the 24-year-old right-hander was nearly flawless. Over five hitless innings, Miller struck out 11 batters and did not issue a walk. His only baserunner reached on a wild pitch that was the result of a swinging strikeout. Miller also lit up the radar gun, reaching 100 mph on 23 of his 64 pitches.

Though the A’s played at the same time as Las Vegas on Friday night, Kotsay received word of the dominant outing and watched highlights of it after the game.

“I think Mason, this year, is throwing more strikes,” Kotsay said. “The results are supporting that. He’s healthy, which hopefully continues. We’re watching his progress and excited about it.”

Through two Minor League outings, Miller has pitched 8 2/3 innings allowing two runs on two hits with no walks and 19 strikeouts.