Clark has been lost for the season with a wrist injury, and Collie will miss the game after undergoing surgery on his right thumb.
Manning expressed confidence Thursday when asked about his depleted group of pass-catchers.
"I really look forward to seeing where we are in this game," the quarterback said. "We'll get better each game with some of the new guys that are going to be playing in different spots. It's an exciting opportunity for these guys."
Wide receiver Anthony Gonzalez is expected to be available after missing four of the past five games with a sprained right ankle, but running back Joseph Addai is considered day to day with a nerve injury in his left shoulder and didn't practice Thursday. Wide receiver Pierre Garcon sat out with a hamstring injury, and the team's top wideout, Reggie Wayne, was limited with a hamstring injury.
At one point, Manning removed "injuries" from his vocabulary.
"It's not something that ... you can just keep drowning yourself with that word," he said. "We have to move on with the guys that are playing."
Even through all the injuries this season, Manning, a four-time MVP, has been dominant. He leads the NFL with a 103.4 passer rating and is tied for third with 13 touchdown passes.
Center Jeff Saturday said the team takes great pride in its depth.
"It's something that we've built ourselves on here," he said. "Tamme's going to have to step in and do well, Gonzo's going to have to come back and be what he can be. Blair White, anybody. Next guy up has got to step up and meet the challenge. I've got faith in those guys."
The Colts acknowledge that losing Clark affects their game plan. Clark's speed and pass-catching skills often have created mismatches and forced defenses to play with additional defensive backs.
"He certainly created some opportunities for us," Colts coach Jim Caldwell said. "Anytime you see a guy in his position catch 100 balls (last year), obviously, he's an integral part of what we do. He's been able to force teams to adjust what they want to do from a defensive standpoint in terms of personnel. Losing Dallas certainly is a bit of a blow to us."
Tamme, a special-teams standout who has six catches in his career and none this season, said his preparation has been similar to other weeks.
"Obviously, there's a few more reps, but mentally, no different," he said. "I think I'm prepared pretty good. Dallas does a good job of getting all of us prepared to play. I've been prepared to play every week. I'll prepare the same way."
White has made six catches for 66 yards this season. He was called up from the practice squad in Week 3 and caught three passes for 27 yards and one touchdown in a win over the Denver Broncos.
"We're not really making an adjustment based on the people that we're missing, we're making an adjustment on the defense that we're playing against," he said. "It's real simple. Just be where you're supposed to be at the time you're supposed to be there -- and make the plays."
"Obviously, losing those guys hurts, but you've got to continue to find ways to win," he said. "They ain't calling any games off."
Copyright 2010 by The Associated Press