The Giants placed Larsen (knee) on injured reserve Wednesday, Michael Eisen of the team's official site reports.
Larsen suffered a knee injury during the third quarter of Saturday's preseason finale against the Patriots, Dan Salomone of the Giants' official site reports.
Larsen reverted back to Tampa Bay's practice squad Monday, per the NFL's official transaction log.
The Buccaneers elevated Larsen (knee) to the active roster Friday, Scott Smith of the team's official site reports.
Larsen (knee) is listed as questionable for Sunday's game against the Saints.
Larsen (knee) is ruled out for Sunday's game against the Raiders.
Larsen (knee) is questionable to return to Sunday's game versus the Vikings, Kevin Fishbain of The Athletic reports.
Larsen signed a one-year contract with the Bears on Wednesday, Larry Mayer of the team's official site reports.
Larsen was released by the Dolphins on Thursday, Adam H. Beasley of the Miami Herald reports.
Larsen is active for Sunday's game against the Colts.