Gallagher will wear No. 36 and be available for tonight’s game in Washington.
The 21-year-old Gallagher begins his second stint with the Cubs in 2007, as he posted no record and a 9.53 ERA (6 ER/5.2 IP) in three relief appearances during his previous stay from June 6-21. He made his big league debut June 9 at Atlanta and tossed a season-high 3.1 relief innings.
Gallagher had pitched exclusively at Double-A Tennessee prior to his first call-up to the Cubs. With the Smokies, he went 7-2 with a 3.39 ERA in seven starts. He made his Triple-A debut when he was optioned to Iowa after his first Cubs stint and has since made two starts, going 1-1 with a 4.00 ERA.
Petrick, 23, has no record and a 3.18 ERA (2 ER/5.2 IP) in four relief appearances with the Cubs this season. He was originally selected from Tennessee on June 26 and has yet to pitch at Triple-A this season. With Tennessee in 2007, Petrick went 1-1 with two saves and a 2.37 ERA (8 ER/30.1 IP) in 18 games.