Lowry's prognosis was among a flurry of injury news the Raptors announced Thursday.
Guard-forward Landry Fields underwent surgery on his ulnar nerve in his right elbow Wednesday in New York. Fields had been suffering from tenderness in his right hand. He will be reassessed in two weeks.
And guard-forward Alan Anderson will be out as estimated three to six weeks with a partially torn plantar fascia in his left foot. He is estimated to be out for three to six weeks.
Lowry has already missed four games after suffering the injury Nov. 6 at Oklahoma City.