Boston Celtics big man Robert Williams banged knees with a Philadelphia 76ers player in the first half of the team's Summer League opener. According to Celtics PR, the injury is a left knee contusion and not considered a major issue going forward.

The team was not certain what Williams' status would be for Saturday's game. He returned from the locker room with the team after halftime, but spent the half with an ice pack on his knee.

Williams came off the bench for the Celtics, entering the game early in the first quarter to replace Guerschon Yabusele.

Williams impressed in his first minutes -- knocking down a mid-range jumper and catching a two-handed dunk from a dump-off pass. He also skied for a rebound. His final stat line: Four points and two boards in 6:45.