Matt Garza was taken out after working three scoreless innings against the St. Louis Cardinals with cramping in his right triceps, an injury that wasn't obvious and prompted speculation that he had been traded.
The Cubs didn't reveal the injury until the bottom of the sixth, adding that X-rays were negative. Justin Germano got unlimited warmups, indicating he was entering the game because of an injury or ejection, when he replaced Garza in a 0-0 game Saturday night.
Germano was acquired Thursday from the Red Sox for cash considerations after being designated for assignment by Boston on July 13.
Garza is 5-7 with a 3.91 ERA, working 10 scoreless innings his last two outings. The Cubs are believed to be shopping both Garza and Ryan Dempster, whose 33-inning scoreless streak ended in a loss at St. Louis on Friday night.
It was the second appearance of the season for Germano, who worked 5 2-3 scoreless innings of relief July 7 against the Yankees.