He is expected to miss the rest of the season.
Over eight games this season prior to suffering the injury, Johnson, a 6-foot-7 guard, averaged 4.5 points and 1.1 rebounds
The Panthers reportedly will apply for a medical redshirt for Johnson.
Pittsburgh has posted a 3-3 record in ACC play so far. The Panthers (13-6) will host No. 10 Louisville on Sunday.