Marrone, underscoring that the team considers Manuel's surgery "very, very minor," said the Bills won't sign another quarterback during the rookie's absence. The team had said Saturday that Manuel will miss the remainder of the preseason. Marrone said Sunday that Manuel has a good chance of returning before the start of the regular season.
"We're not going to pursue that right now to bring somebody else in which I think says a lot. We're going to evaluate it after the preseason and take it day by day after that," he said, according to the team's website.
Marrone said he hasn't spoken to doctors to see how the surgery went as the Bills were on the practice field at the time of the procedure, which was performed in Buffalo.
Manuel, the Bills' first-round pick in April's draft, suffered the injury in Friday night's preseason game.
It's unclear when or how Manuel was hurt in the 20-16 win over Minnesota. He took over to start the second half and opened with a 14-play, 80-yard drive capped by a 4-yard touchdown pass to Brad Smith. He finished 10 of 12 for 92 yards in three series.
Manuel told Marrone that he believed the injury occurred on his sixth play of the game when he scrambled to his right for a five-yard gain. That play was called back on a holding penalty.
Kevin Kolb noticed something was wrong with Manuel after that scramble.
"You can tell when you're around a guy a lot and the way he runs and the way he acts and the way he grimaces, it just looked like something was a little wrong," Kolb said. "And when he came to the sideline, he really wasn't talking to anybody that much, so I could tell something was on his mind and I just left him alone."
Through two games this preseason, Manuel completed 26 of 33 passes for 199 yards and two touchdowns, and ran four times for 29 yards.
Kolb signed with the Bills in the offseason after starting 21 of 32 career games played in a six-year career with Philadelphia and Arizona. He's thrown for 28 touchdowns and 25 interceptions while being sacked 77 times in a career that started as a second-round draft pick of the Eagles in 2007.
Information from The Associated Press was used in this report.