Athletics manager Bob Melvin said Anderson (shoulder) remains shut down and has yet to initiate baseball activities, Jane Lee of MLB.com reports.

EDGE Analysis

It's been almost two weeks since Anderson exited his May 18 start with a strained left shoulder, so the fact that he hasn't even kicked off a throwing program yet suggests that he'll be in for at least a month-long absence. Frankie Montas was recalled from Triple-A Nashville and took the hill Sunday against the Diamondbacks with Anderson missing out on another scheduled turn through the rotation.