The announcement came a little more than two weeks after Collie was diagnosed with his third full-blown concussion in less than 22 months. Coach Chuck Pagano said the team put Collie through a battery of tests before allowing him back on the field Monday.
Teammates and coaches insist Collie's healthy.
"You talk to Austin, he acts like nothing ever happened," said cornerback Jerraud Powers, a close friend of Collie's. "I'm sure he'll do what's best for his family and himself, and when you see him out there, it gives us a lot of excitement."
Having Collie back is a huge boost for a revamped Colts team looking to rebound from an awful 2-14 mark last season.
In three years, the Brigham Young alum has caught 172 passes for 1,839 yards and 16 touchdowns, and his experience should provide new quarterback Andrew Luck with another capable outlet against the Bears' vaunted defense.
Few people question Collie's talent. The concern is his history of head injuries.
Collie sustained two diagnosed concussions in the second half of the 2010 season, the first at Philadelphia when he was knocked out cold and wound up leaving the field on a stretcher. He left a third game that year with what the team described as "concussion-like symptoms." Colts officials never said it was diagnosed as a concussion.
He made it through last season without any known relapses, but left early in the Colts' second preseason game after taking another shot to the head, this time from Pittsburgh linebacker Larry Foote. Some of Collie's teammates thought Foote should have been penalized, though no flag was thrown and league officials did not fine Foote.
Collie hadn't even practiced again until Monday, when Pagano told reporters that Collie was "full go."
When asked how Collie performed, Pagano said: "Great, fresh legs, ran all over the place, looked good."
While Collie made a brief appearance in the locker room, he slipped out before taking questions from reporters.
Those who were on the field echoed both Pagano's scouting report and Powers' personal sentiment.
"Yeah, he looked like the same, old Austin. He was catching passes, running good routes," safety Antoine Bethea said. "If he didn't think he was ready, I don't think he'd be out there."
Pagano said three other starters -- left guard Mike McGlynn (sprained left ankle), Powers (sprained knee) and defensive end Cory Redding (strained right knee) -- are all expected to play against the Bears, too.
McGlynn hasn't played since getting hurt early in last month's preseason opener. Redding missed the first game, then hurt his knee in Week 2 at Pittsburgh and missed the last two preseason games. Powers also was injured in Week 3 and was held out of the preseason finale as a precaution.