The Los Angeles Dodgers recalled right-hander Michael Petersen on Monday and optioned left-hander Justin Wrobleski to Triple-A Oklahoma City.
Peterson, 30, made his major league debut June 18 and went 3-0 with a 4.50 ERA in nine relief appearances over two separate stints with the Dodgers earlier this season. He was in his eighth minor league season before making his MLB debut.
Wrobleski, 24, was called up to face the Arizona Diamondbacks on Sunday and was crushed for 10 runs on 10 hits in 5 1/3 innings. Since making his major league debut July 7, Wrobleski is 1-2 with a 6.82 ERA in six starts.
The Dodgers entered play Monday with the best record in the major leagues at 82-55, one game better than the Philadelphia Phillies.