A's activate RHP James Kaprielian, option RHP Adam Oller

The Oakland Athletics made it official Sunday, activating right-hander James Kaprielian in advance of his season debut against the Cleveland Guardians.

Right-hander Adam Oller was optioned to Triple-A Las Vegas.

Kaprielian was impressive as a rookie last season, going 8-5 with a 4.07 ERA in 24 games (21 starts). He is making his first appearance against the Guardians.

Oakland has been exercising patience with Kaprielia