The A's announced they optioned Opening Day starter Kendall Graveman to the Minors on Thursday.

With an 0-5 record and 8.89 ERA over six starts, Graveman will be sent to Triple-A Nashville with right-hander Chris Bassitt. Oakland added righty Wilmer Font, acquired from the Dodgers on Wednesday, to the 25-man roster.

Graveman gave up 28 runs and 41 hits -- both Major League highs -- but had a promising start (6 IP, 3 ER) on Wednesday against the Rangers, particularly with his changeup.

"He mixed his pitches again and overall threw better, we just didn't score too many runs for him," A's manager Bob Melvin said. "We just didn't play a good game overall."

Graveman experienced a similar beginning to the 2015 season, when he posted an 8.27 ERA in four starts, which also resulted in a Minor League demotion. He came back the following month and went 5-2 with a 1.78 ERA over his subsequent nine starts.

Bassitt, whom the A's recalled from Nashville last Friday, didn't pitch in a game while on the roster. It would've marked his first MLB appearance since undergoing Tommy John surgery in May 2016. The righty is 1-0 with an 0.69 ERA in three relief outings with Nashville.