Anderson suffered the injury on the final play of the first quarter. He was tackled by UCLA's Rick Wade and Adarius Pickett after a 10-yard run and came up holding his right knee. He limped off on his own and was taken to the locker room.
"We'll see on Rodney," coach Lincoln Riley said after the game. "Don't have anything definitive. We'll hope for the best."
During his past seven games last season, including the bowl, Anderson led the FBS in yards from scrimmage. In the CFP loss to Georgia in the Rose Bowl, Anderson rushed for 201 yards and two touchdowns.
He finished the 2017 season with 1,161 rushing yards and 13 touchdowns while catching five touchdown passes
In the opener against Florida Atlantic last weekend, he finished with 100 yards and two touchdowns on only five carries.
Anderson suffered a season-ending leg injury two games into his freshman season. The following spring, he injured his neck, knocking him out for the year again.
Anderson exited Saturday with 19 yards on six carries and a touchdown. Sophomore Trey Sermon replaced him in the Oklahoma backfield.