Carolina Panthers quarterback Cam Newton has been ruled out for Monday night's game against the Tampa Bay Buccaneers because of a concussion.
The league's MVP hasn't practiced since taking a helmet-to-helmet hit in Sunday's 48-33 loss to the Atlanta Falcons.
Derek Anderson will start for Carolina in Newton's place.
It's unclear when Newton will return. The Panthers visit the New Orleans Saints on Oct. 16 and then have a bye the following week.
Panthers Coach Ron Rivera described Newton as "antsy," adding that "he can't help himself."
This is only the third game Newton has missed since joining the Panthers as the No. 1 pick in 2011.
"We're going to do what we do, play who we play," Rivera said after Saturday's practice. "We've done this before. It's that next-man-up mentality."
Carolina will also be without three other starters on Monday — running back Jonathan Stewart (hamstring), left tackle Michael Oher (concussion) and cornerback James Bradberry (toe). Defensive tackle Vernon Butler (ankle), the team's first-round draft pick, is also out.
Outside linebacker Thomas Davis (hamstring), defensive end Charles Johnson (quad) and fullback Mike Tolbert (hamstring) are listed as questionable.
Lawrence likely to play for Cowboys
The Cowboys have activated DeMarcus Lawrence for Sunday's game against Cincinnati, clearing the defensive end for his season debut after a four-game suspension for violating the NFL's substance-abuse policy.
Lawrence was the sacks leader for Dallas with eight last year. The third-year player was one of three defensive starters suspended to start the season for substance-abuse violations. Linebacker Rolando McClain is serving a 10-game suspension, and defensive end Randy Gregory is out 14 games for two violations.
The Cowboys (3-1) have six sacks, and Tyrone Crawford leads the team with two after moving from defensive tackle to end three games into the season.