The only thing you knew about Carmelo Anthony and his ongoing knee problem is that he wasn’t expected to play Monday night in the wrap-up game of the Knicks’ five-game trip from hell. We really still don’t know what caused him to miss the last 3½ games of the trip, or what started the problem during a Feb. 13 loss to Toronto when he first experienced soreness in the back of his right knee. What’s the rush, right? The playoffs only start in a month and change. The diagnosis Anthony provided at the morning shootaround — the first time he had talked to the media since going back to New York Thursday to have his knee drained and to get to the bottom of what caused the buildup of fluid — seemed dubious, at best. A hamstring pull? That might be a first in medical history, since orthopedic surgeons usually find a problem inside the knee when fluid is found. Usually it’s a cartilage tear. Or maybe a Baker’s cyst, the kind they found in Amar’e Stoudemire’s left knee back in October. Sometimes, it’s the on-set of an arthritic condition. But a bad hammy? C’mon.