Jenkins underwent right elbow debridement surgery Wednesday, Bobby Nightengale of the Minneapolis Star-Tribune reports.
Buxton had the stitches removed from his surgically repaired right hip earlier this week and has begun the rehab process, Dan Hayes of The Athletic reports.
Bell went 1-for-2 with a home run, a walk and three RBI in Sunday's 6-4 win over the Rangers.
Kremer (5-5) earned the win against the Rangers on Sunday, allowing one run on three hits and no walks with four strikeouts over seven innings.
Lewis went 2-for-4 with a solo home run and a stolen base in Sunday's 6-4 win over the Rangers.
White went 2-for-3 with an RBI in Saturday's 13-2 loss to Houston.
Johnson will serve as the Athletics' opening pitcher for Sunday's game against the Astros, Martin Gallegos of MLB.com reports.
Williams (upper body) is not in the starting lineup for Friday's game against the Astros.
Williams was scratched from Thursday's contest versus Houston with upper-body soreness, Martin Gallegos of MLB.com reports.
Williams (undisclosed) was scratched from Thursday night's lineup against the Astros, Martin Gallegos of MLB.com reports.
