Wallace, who came out of retirement to play for the Knicks this season, has been out of the lineup since Dec. 13 with the foot injury.
The team said a recent exam of Wallace's foot revealed a fractured fifth metatarsal bone. He is scheduled to undergo surgery this week.
The 38-year-old, four-time all-star averaged 7.2 points and 4.2 rebounds per game over 20 contests this season before sustaining the injury.
Over 1,108 games in his 15-season career, Wallace has compiled averages of 14.4 points, 6.7 rebounds, 1.8 assists and 1.3 blocks while playing for Washington, Portland, Atlanta, Detroit, Boston and New York.
Scarlett Johansson steps out with fiance after pregnancy reveal
Dennis Rodman pledges to end trips to North Korea