Joel Freeland has been ruled out for four to eight weeks after spraining his MCL during the Portland Trail Blazers' defeat to the Oklahoma City Thunder.
The forward and center sustained the injury during the fourth quarter of the 98-95 loss, and had to be helped from the court.
The 27-year-old Briton has mainly been used to spell starting center Robin Lopez this season, averaging 3.3 points per game.
The Blazers play again tonight against the Los Angeles Clippers.
