Rasheed Wallace, one of the oldest Knicks on a team filled with veterans, will have season-ending surgery on his injured left foot, the team announced Wednesday afternoon. A new X-ray examination of Wallace’s foot found that he had a fractured fifth metatarsal. Wallace is scheduled to have surgery later this week. The team said Wallace is expected to be out for eight weeks, which covers the remainder of the regular season. It is unclear if Wallace would be able to play in the postseason should the Knicks reach the playoffs, which appears likely. Wallace sustained what was originally called a stress fracture in his foot in a win over the Los Angeles Lakers on Dec. 13, and has not played since. The Knicks were reluctant to have Wallace undergo surgery because they believed the injury would heal without it. When Wallace, 38, was on the court, he provided veteran leadership and defensive savvy. He was one of the many surprises that help propel the Knicks to an impressive start. The Knicks won 11 games in November and Wallace played in 14 of their 15 games. After Wallace’s last game of the season, the Knicks were 17-5 and atop the Eastern Conference standings. He averaged 7.2 points and 4.2 rebounds in 20 games.