Beckham would miss Sunday night's game at Minnesota. He has the right to appeal the suspension that was announced Monday.
Beckham and Panthers cornerback Josh Norman tangled from the beginning of the Panthers' 38-35 victory. At one point, Beckham delivered a diving helmet-to-helmet hit on Norman while blocking, but he was not ejected from the game.
The NFL said in a statement Sunday that the decision to eject a player can be made by the on-field officials only.
There was plenty of pushing, shoving, swinging, wrestling, late hits and trash talking between Beckham and Norman.
The Giants (6-8) would lose their top offensive weapon for a game they almost certainly must win to remain in the NFC East race.
Beckham, the 2014 Offensive Rookie of the Year, has 91 catches for 1,396 yards and 13 touchdowns, tied for the league lead.
Information from The Associated Press was used in this report.