The Colts originally said Wentz, who had foot surgery on Aug. 2, would be limited in practice this week. So much for that.
Wentz took all the first-team reps in 7-on-7 work and didn't give way to a backup quarterback until nearly an hour into practice. Receiver Zach Pascal said Wentz was "clicking on all cylinders" in his first practice since July 29.
"When I first saw him hopping around out there, I thought his movement looked pretty good," Colts coach Frank Reich said.
Reich said he was a little surprised to have Wentz back just three weeks after his surgery. The Colts originally said Wentz would be out five to 12 weeks.
"What helped was surgery was the best-case scenario and recovery was really quick," Reich said. "Feels like he's a week ahead of schedule."
Wentz said he is hopeful he can return for the Colts' Week 1 matchup against the Seattle Seahawks.
"I'm optimistic, but we'll see how it responds," Wentz told reporters after Monday's practice. "As long as there's nothing I can do to make it worse, I've played through a lot worse."
Reich said last week that he would like for Wentz to have at least two weeks of practice before playing in a regular-season game. He could have almost three weeks of practice before facing the Seahawks as long he doesn't suffer any setbacks.
"It's going to have to be," Wentz said when asked if three weeks is enough time to get ready for the regular season. "Would love to get as many reps as I can out here. It's the hand I've been dealt."
A key will be how Wentz responds daily.
"Have to get to the point where he can do consecutive days' work and then get to point where he can do everything," Reich said. "Still not there."
All-Pro guard Quenton Nelson, who had the same surgery as Wentz earlier this month and was given the same timetable, and center Ryan Kelly, who had been out with left elbow injury, also returned to practice Monday.