The Indianapolis Colts have signed rookie receiver Nathan Palmer to their active roster, a possible indication Austin Collie will be lost for an extended time.

Palmer was a member of the San Francisco 49ers practice squad, but confirmed today via his Twitter account he is relocating.

“ . . . I’m (excited) for a new opportunity in my home state!,’’ he wrote. “Coming home mom and dad!!!’’

Palmer attended Elkhart Central H.S. and was a college teammate of Colts’ rookie quarterback Chandler Harnish at Northern Illinois.

The addition of the 5-11, 195-pound Palmer might indicate the severity of a knee injury suffered by Collie in Sunday’s loss to Jacksonville. Collie grabbed his right knee after catching a 6-yard pass from Andrew Luck. He had to be helped off the field and was taken to the locker room on a cart.

After game, coach Chuck Pagano said, “Feel just terrible for Austin. Just terrible, terrible thing fighting what he’s fought through and then to have something like this happen.’’

A magnetic resonance imaging test was scheduled, but the team has not commented on the results.

Collie missed the first two games this season after suffering a concussion Aug. 19 at Pittsburgh. He missed the final seven games in 2010 after suffering multiple concussions.

Call Star reporter Mike Chappell at (317) 444-6830.