Kevin Kolb, Manuel's competitor for Buffalo's starting quarterback job, will serve as an emergency QB as he makes his way back from a left knee injury.
Kolb returned to practice Friday, but he was limited and did not take part in any team drills after missing time because of a death in the family. Kolb had been excused from training camp since Monday afternoon.
At Friday's practice, Kolb went to the locker room a little over an hour into the workout to receive treatment on his knee. He hurt the knee last Saturday when he tripped on a mat between the Bills' practice fields.
"Not having him in the treatment, being away for a couple days because of a personal issue, I think that it's a little tight," Marrone said.
"He is going to dress, he is going to be there and then knock on wood if we don't need the third quarterback, if we do need one, we'll put him in there and obviously he'll just be handing the ball off and not put him in jeopardy."
Manuel was the 16th overall selection in the 2013 NFL Draft.
"I'm very excited," Manuel said about his first preseason start. "I think we've worked out very hard these past two weeks and I know I'm going to be very excited to play against a different team. ... I think the biggest thing is to just go out and relax and play football."
Cornerback Leodis McKelvin (groin) and wide receiver Brad Smith (undisclosed) will not play for the Bills. McKelvin, who had groin surgery in the offseason, has been dealing with soreness since the team's night practice Monday. Marrone said McKelvin met with team doctors Friday night for further evaluation.
The status of defensive end Mario Williams (sore foot) will be determined in warmups before Sunday's game, Marrone said. Williams participated in practice Friday, but he's making his way back after missing the start of camp.
Copyright 2013 by The Associated Press