INDIANAPOLIS -- Peyton Manning has lost another of his top targets for the season.

Colts receiver Austin Collie suffered a concussion Sunday against Jacksonville, and the team placed him on injured reserve Wednesday.

Though Collie is in his second year, Manning feels as if he's losing a veteran. Despite missing five games and more than a half in three others, Collie leads all Colts receivers with eight touchdown catches, is second in receptions (58) and third in yards (649).

"He's fast, he's got a good feel for zones, he understands defenses," Manning said. "He has his physical talents, but also, his experience has helped him play at such a high level at such a young point in his career."

Collie was injured late in the first half against Jacksonville when linebacker Daryl Smith appeared to hit him in the head with his forearm as Collie went low to make a catch. It was his second concussion of the season.

"He certainly is a guy that's going to be missed," Colts coach Jim Caldwell said. "From a medical standpoint, we are concerned more so about his health than anything else. This is the right thing for him at this particular time."

Manning had already lost tight end Dallas Clark and receiver Anthony Gonzalez for the season, and running back Joseph Addai has missed the past eight games with a shoulder injury. But the Colts (8-6) are fighting for a playoff spot, and don't have time to feel sorry for themselves heading into Sunday's game at Oakland (7-7).

"It doesn't do you any good to think about who's not playing and who's not going to be available," Manning said. "You have to go with who's available, and feel like with who's available, you can go out there and still make things happen."