Rasheed Wallace’s surgery in which a screw was inserted into his left foot Thursday at the Hospital for Special Surgery was done with his goal of returning sometime during the playoffs. Wallace could have just called it a career, placed a cast on the foot for 12 weeks and been done with basketball. According to a source, he contemplated that possibility the last several days. The Knicks, however, announced an eight-week timetable that could put him back on the court in the middle of the first round. But one leading medical expert said Wallace will not be at 100 percent healed after just eight weeks from surgery to repair a Jones fracture of his fifth metatarsal. Dr. Anish Kadakia, assistant professor of orthopedic surgery at Northwestern University who specializes in Jones fractures, told The Post Wallace could be running in six weeks. Nevertheless, he wouldn’t be 100 percent for 12 weeks. “After eight weeks, he’ll probably be 90 percent,’’ Dr. Kadakia said. “One hundred percent after eight weeks is not possible and it is a higher risk of failing. But these guys have everything under the sun [to rehab] but speed and jumping is compromised if it’s just eight weeks.’’ Dr. Kadakia has not treated Wallace, but is basing the injury on reports Wallace had a stress reaction before turning into a fracture. “It is six to eight weeks for an athlete when there’s money riding on it,’’ Dr. Kadakia said. “You can let them go back and play if it’s important like the playoffs. The screw is big enough and strong enough to tolerate the stress you put on it. Those fractures do very poorly without surgery.’’ The Knicks are hopeful Wallace can come back because he’s only needed for about 12 minutes a night. If backup center Marcus Camby can’t stay healthy and Kenyon Martin is a bust, Wallace could be a help deep in the second round.