McGee, who went 2-3 with a 4.73 ERA last year -- part of which he spent as the Rockies' closer, has been more aggressive than usual in early work during Spring Training. His next spring appearance is Friday against the Indians in Goodyear, Ariz., and after a bullpen session Sunday, he'll join Team USA.
"In the future, I'm going to work out all offseason just to keep my knee strength up -- last year, it really stood out when I didn't have a foundation pitching, and in everyday life, too," McGee said. "When my knee is really weak, it's hard to do things. But with what I did all offseason, I feel great now."
McGee said he's had radar readings during live batting practice sessions -- with a batting cage, no umpire or fans -- and he's thrown 93 mph, just going about 80 percent.
"The plan is to stay within myself the first game, maybe push a little more the second game, and we'll see after that," McGee said. "But in my bullpens, for the last 10 pitches, I act like I'm facing hitters. I'm taking signs from the catcher and ramping up a little bit."
New manager Bud Black said Rockies personnel "were saying there was a marked difference between how he looked a year ago and how he looks now, with his delivery, his motion and driving down the mound."
Athletics righty Sonny Gray and Blue Jays catcher Russell Martin have backed out of the Classic after being denied insurance. They were classified as "chronic condition" players, having spent more than 60 days on the disabled list last season. McGee was the Rockies' closer before going to the disabled list with left knee inflammation after a June 10 appearance, but he returned July 2.
McGee and the Indians' Andrew Miller are the two lefties in the USA bullpen.
Thomas Harding has covered the Rockies since 2000, and for MLB.com since 2002. Follow him on Twitter @harding_at_mlb, listen to podcasts and like his Facebook page. This story was not subject to the approval of Major League Baseball or its clubs.