The 28-year old Grimm was optioned to Triple-A Iowa July 31 and appeared in two games, allowing just two hits and no runs in 3.0 innings pitched. He struck out five batters and walked none. Overall in eight games this season with Iowa, he has gone 0-1 with a 3.72 ERA (4 ER/9.2 IP).
Grimm has appeared in 36 games with the Cubs this season, going 1-1 with a 5.18 ERA (23 ER/40.0 IP). This will mark his fourth stint with the club as he was previously in the majors from Opening Day-May 4, May 7-10 and May 29-August 1.
Uehara, 42, is 3-4 with 13 holds, two saves and a 3.55 ERA (15 ER/38.0 IP) in 43 relief outings with the Cubs this season.