"They can't get hurt," Callaway said. "If they get hurt, they've still got to play."
McKinzey is Fernando Velasco's backup at tight guard.
The depth issues will put more spotlight on incoming freshmen linemen Chris Davis and Josh Davis, but Callaway was unwilling Saturday to speculate on which of those players might have a chance to contribute.
"It's so hard to tell. It's a different ball game (in college)," he said. "We'll get the pads on in a couple days, and we'll start making evaluations then."
(True freshman John Miller hasn't been cleared for contact after offseason shoulder surgery and probably won't play this season.)
Coach Mark Richt would like to redshirt every freshman offensive lineman in this class, he said.
"I don't know if I'll be able to because one or two of them may have to be starters for us next year," he said.
Kevin Perez is the only other freshman lineman to qualify this year. He currently is listed as the No. 2 center, but McKinzey will be trained at center as well, Callaway said.