To make room for Gee, the most obvious corresponding move would be to place left-hander Mike Minor on the 60-day disabled list. Minor missed the 2015 season because of a torn labrum and likely won't be available for a Major League callup until at least mid-June.
Gee said he hasn't given much thought to his opt-out clause, which must be exercised by midnight ET on Tuesday.
"Really not much at all," Gee said. "My main focus here has been to get my work in and pitch well. After that, everything will take care of itself.