Athletics' Zach Jackson: Out indefinitely after appendectomy

Jackson (elbow) underwent an appendectomy Monday and is without a timeline to resume his rehab program, Martin Gallegos of MLB.com reports.

Jackson has made two minor-league appearances in the past week as he works on returning from a strained elbow, but his recovery from the appendectomy will put a pause on his rehab indefinitely. He struck out four and allowed two earned runs in two innings across the two rehab appearances. The right-hander has been on the injured list since mid-May.