The success of rookie relief pitchers Aaron Loup and Chad Jenkins in a suddenly deep Toronto Blue Jays bullpen allowed the team to deal from a position of strength on Friday.
General manager Alex Anthopoulos moved right-hander Jesse Chavez to the Oakland Athletics for cash considerations.
Chavez, 29, appeared in nine games including two starts this season for the Blue Jays, posting a 1-1 record and 8.44 earned-run average.
He began the season pitching at AAA Las Vegas, where he went 8-5 with a save and 3.98 ERA over 19 appearances (17 starts).
Chavez, whom the Blue Jays claimed off waivers on Oct. 21, 2011, is 7-11 in 152 major league games with a 5.74 ERA for Pittsburgh, Atlanta, Kansas City and Toronto.
Later Friday, Oakland recalled right-hander Jim Miller from AAA Sacramento and optioned pitcher Tyson Ross to the Pacific Coast League club.
Ross was recalled Thursday to start against Tampa Bay after Bartolo Colon was suspended 50 games on Wednesday for testing positive for testosterone. Ross will work out of the bullpen at Sacramento.
Miller went 2-1 with a 2.16 ERA over 24 games in two earlier stints with the Athletics this season.