Oakland Athletics left-handed prospect A.J. Puk is set to undergo season-ending surgery Wednesday on his pitching shoulder.

Puk hasn't pitched this season because of inflammation in the shoulder that required injections. He also underwent Tommy John surgery on his left elbow in 2018.

"For A.J., obviously, it's been a tough road for him," manager Bob Melvin told reporters. "Back and forth, ramping up, having to shut down. Obviously there's something going on that he needs to take care of."

Puk, 25, had been set to join the Athletics rotation in 2020 after making 10 relief appearances in 2019, going 2-0 with a 3.18 ERA in 11 1/3 innings.

Also, Athletics third baseman Matt Chapman, who hasn't played since Sunday, visited a doctor in Vail, Colorado, on Friday for another opinion on his right hip tendinitis.

Chapman is hitting .232 with 10 home run and 25 RBIs this season.

The Associated Press contributed to this report.