McCareins injured his hamstring in Wednesday's practice, and Gage has not practiced in three weeks because of a right knee injury.
McCareins said he will be a game-time decision.
"It'll be a pregame type decision. I'll go out early and try to sprint around a little bit and see how it holds up," McCareins said. "It was just a minor tweak on the lower hamstring. It's kind of frustrating.
"I was dealing with a different part of the same leg during training camp. I hadn't noticed it. This caught me off guard. This is a different spot on the leg."
Brandon Jones started in place of Gage at Baltimore and if both receivers are out, it could open up more playing time for Chris Davis or rookie Lavelle Hawkins who has been active in just two games and has not caught a pass thus far.
Hawkins said he hopes the extra work during the bye week and this week with the starters has helped him.
"I think I got a whole lot better," Hawkins said. "As they let you work toward the ones or with the ones, you've got to minimize your mistakes. I've just been more focused in my (play)book, trying to minimize my mistakes. That's been my problem is making mistakes, and that's why I've been on the bench for so long."
Defensive end Kyle Vanden Bosch and defensive tackle Tony Brown both were limited in practice Friday and will be questionable. Brown practiced for the first time this week on Friday and Vanden Bosch has practiced the past two days.
Rookie tight end Craig Stevens was out of Friday's practice with a foot injury and is probable against the Chiefs.