The 26-year-old left-hander has pitched mostly in the middle innings, but he has opened eyes with the way he has performed.
McGee is equipped with a fastball that's clocked as high as 97 or 98 mph, and he's evolved into a pitcher capable of getting out hitters from either side of the plate.
In McGee's past 16 appearances, he has not been charged with a run. During that period, he has struck out 19 and allowed just four hits.
McGee's slider has developed nicely to complement his fastball and, according to Rays manager Joe Maddon, he has the calm makeup necessary for the job.
"When you're out on the mound and a guy comes in, when you give him the ball, what does he look like?" Maddon said. "What do his eyes look like? Is he breathing well? What's he all about? He is outstanding, because he comes in, you bring him in during the course of an inning, and he's always good."