PHOENIX -- To make room for recently claimed left-handed reliever Wil Ledezma, the D-backs optioned right-hander Billy Buckner to Triple-A Tucson on Saturday.
In three stints with the D-backs, Buckner has gone 1-0 with a 3.60 ERA in 10 innings. Buckner will be back in Phoenix after the Sidewinders' season ends on Tuesday. Major League rosters can expand to up to 40 players on Monday.
Ledezma, who was claimed Friday on traditional outright waivers from the Padres, will be used a long reliever or against left-handed hitters late in the game. The D-backs have been without a left-hander in the bullpen for a good part of the second half of the season.
Doug Slaten came off the disabled list for his right knee strain but has appeared in only three games since the All-Star break. Slaten will be among the team's several September callups.
Asked what it was like to join a pennant race after being on a last-place team all season, Ledezma said: "I can't even explain it. It's big."
Ledezma is no stranger to being in a pennant race, as he was a member of the Tigers' 2006 World Series team.
Ledezma, used as a starter and a reliever for the Padres this year, went 0-2 with a 4.47 ERA (27 earned runs in 54 1/3 innings) over 25 games, striking out 49 and walking 38.
Mike Ritter is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.