Dr. Mark Adickes discusses the torn meniscus suffered by Steelers quarterback Ben Roethlisberger and speculates on the timeline for recovery, saying Roethlisberger could return as early as Week 9. (1:07)

Pittsburgh Steelers quarterback Ben Roethlisberger has a torn meniscus in his left knee and will undergo surgery Monday morning, a league source told ESPN's Adam Schefter.

Editor's Picks Steelers positioned to survive Ben Roethlisberger knee injury

The source said doctors expect the procedure on Roethlisberger's knee to be a "cleanup," not a full repair of the meniscus, and this generally favors a quicker recovery.

The Steelers won't know how long Roethlisberger will be sidelined until after the surgery, but he will definitely miss at least next Sunday's game against the New England Patriots, according to the source.

Speaking on WEEI's Kirk and Callahan Show on Monday, Patriots quarterback Tom Brady said he expects Roethlisberger back on the field sooner than later.

"He's one of the toughest guys in the league. I would never rule him out for anything," Brady said. "... He's done that before and played and thrown for 400 yards. He's just a stud, just an incredible player. I've played against him since 2004, and nothing surprises me with him. He's one of the best quarterbacks I've ever played against. I would never count him out."

Roethlisberger's injury was first reported by the Pittsburgh Post-Gazette and confirmed by ESPN.

The Steelers have no timetable yet for Ben Roethlisberger's return after he tore the meniscus in his left knee against the Dolphins on Sunday, a source told ESPN. AP Photo/Wilfredo Lee

Roethlisberger was sidelined with 8:18 left in the first half of Pittsburgh's 30-15 loss to the Miami Dolphins on Sunday. He was running a bootleg away from Dolphins defensive end Mario Williams, who appeared to nick Roethlisberger's leg as the quarterback made his way out of the pocket.

Roethlisberger said after the game that he "felt something funny in my knee," which prompted a trip to the locker room.

Upon a first evaluation, the team doctor thought Roethlisberger's leg had hyperextended from the contact, said Roethlisberger, who also has bruising in his right knee from a separate, late-game collision.

Backup Landry Jones played one full series in place of Roethlisberger, who finished 19-of-34 for 189 yards, one touchdown and two interceptions. Roethlisberger played the entire second half.

Roethlisberger Injury History Ben Roethlisberger has missed at least one game because of injury in eight of his 13 NFL seasons. Roethlisberger sat out four games last year because of a knee injury and missed another start in Week 10, but he came off the bench in that game because of an injury to Landry Jones. Roethlisberger also left a 2015 wild-card game against the Bengals because of a right shoulder injury, but he returned to lead the team on a game-winning drive. Ben Roethlisberger Games Missed Due To Injury -- Career Season Games Missed Injury 2016 ? Torn meniscus 2015 4 Knee 2012 3 Shoulder 2011 1 Ankle 2009 1 Concussion 2007 1 Ankle 2006 1 Appendix 2005 4 Knee 2004 1 Ribs >>Steelers: 8-8 in those games

-- ESPN Stats & Information

ESPN's Jeremy Fowler and Mike Reiss contributed to this report.