Beckham went down clutching his knee after attempting to make a tackle following a Baker Mayfield interception in the first quarter. He was ruled out after going to the locker room.
The 27-year-old will have an MRI on his knee Monday morning, head coach Kevin Stefanski said postgame, according to Nate Ulrich of the Akron Beacon Journal.
Browns center J.C. Tretter also suffered an injury on the play. Tretter returned to the game after being evaluated on the sidelines.
Beckham has played in every game through the first seven weeks of the season, amassing 23 receptions for 319 yards and three touchdowns.
The three-time Pro Bowler is in his second season with the Browns. He racked up 1,035 yards and four scores on 74 catches through 16 games in 2019.
Cleveland entered Week 7 without starting tight end Austin Hooper, who underwent an appendectomy.
Rashard Higgins carried the receiving load for Cleveland after Beckham's exit, notching six receptions for 110 yards against the Bengals.