PHOENIX -- Jesse Chavez officially became a member of the A's starting rotation Monday.

Chavez, who has only ever pitched relief since joining the A's and who has just two big league starts in 191 appearances, is down to start Tuesday's game against the Chicago White Sox in Glendale.

He's been pressed into service with the A's suddenly coming up two starters short for the start of the season. A.J. Griffin will not pitch until May after developing pain in his right forearm/elbow. And Jarrod Parker is in Florida today to have Dr. James Andrews examine his right forearm, which has been a problem since late in the 2013 season.

The A's got lobbied hard by Chavez to be in the rotation, not by words but by deeds. In an 18-inning game last year against the Yankees, Chavez pitched the final 52/3 innings June 13 to pick up the win by not allowing a run.

"Chavez was always one of the guys we targeted to be a starter because of his stuff and his repertoire," manager Bob Melvin said Monday morning. "That game against the Yankees was a stepping stone for him."

As the A's rotation stands now, it's Sonny Gray, Scott Kazmir, Dan Straily, Tommy Milone and Chavez. If Parker makes it back in time to be in the rotation for the start of the season, it would be Chavez and Milone competing for the final starting job with Chavez, who hasn't allowed a run this spring in 12.2 innings, the current heavy favorite.

Gray and Kazmir are the opening day candidates. Gray hasn't pitched as well as Kazmir the first three weeks of the Cactus League, but he could turn that around in his final starts.

For more on the A's, see John Hickey's Inside the A's blog at ibabuzz.com/athletics. Follow him on Twitter at twitter.com/JHickey3.