Cubs Manager Dale Sveum said Friday a magnetic resonance imaging exam "came back very clean" except for showing a slight fluid buildup in the triceps area.
That has caused cramping, which forced him to leave his latest start against the St. Louis Cardinals Saturday after pitching three innings.
"He's doing better," Sveum told the Chicago Tribune. "We'll wait and see what happens with his throwing program. It's possible (he'll start) maybe late next week."
Any team seeking to obtain Garza from the last-place Cubs would likely want to see the MRI of his pitching arm, the newspaper said.
Garza is 5-7 with a 3.91 earned run average in 18 starts this year.