NEW YORK (AP) _ Forward Buck Williams of the New York Knicks underwent arthroscopic surgery on his left knee on Friday and was placed on injured reserve.

The 37-year-old veteran is averaging 4.8 points and 4.4 rebounds a game. General manager Ernie Grunfeld said Williams is expected to be out 3-to-6 weeks.

Williams' role with the Knicks is expected to be filled by Terry Cummings, obtained Thursday in a trade with Philadelphia.