Span has been out with a sore right shoulder since Sunday, after trying to make a diving catch in center. Revere, meanwhile, rolled his right ankle while trying to beat out a throw at first base in Wednesday's game against the Tigers.
Span is making progress but isn't quite ready to even serve as a pinch-hitter or pinch-runner off the bench.
"He feels better, but he's not ready to go out there," Twins manager Ron Gardenhire said. "He's going to do some more work in the cage and then get out there in [batting practice] and see what happens. But he's not ready, so we're still a little thin."
Revere's injury is less severe, as he stayed in the game after rolling his ankle and tripled in his next at-bat. He was available off the bench, if needed, and is expected to return to the starting lineup this weekend.
"There's some swelling, a little black and blue today," Twins assistant general manager Rob Antony said. "He's sore, but he's available. He said, 'If you need me, I can play.'"
With Span and Revere out, Darin Mastroianni made his first start in center field while Matt Carson made his Twins debut in right field. Pedro Florimon also made his Minnesota debut, starting at shortstop.