As most of the players cleared off the practice floor, Tyson Chandler took his normal defensive stance and faced off against Chris Copeland, cautiously going through the motions to try to stop him. But after just a few moments he walked off the court, spoke to the Knicks training staff and showed exactly where the bulging disk in his spine was still causing him problems. For Chandler, the desire to get back in the lineup was countered by the knowledge that tonight’s game against the Boston Celtics is not as important as the ones that the two teams could be contesting a month from now. And even if every one of the Knicks’ remaining games is important to playoff positioning, discretion seemed to be the better part of valor. Kevin Garnett underwent an MRI on Sunday on his painful left ankle. The Celtics will be without him tonight and likely when the teams meet again Sunday in New York. The Knicks weren’t ruling out Chandler yet, calling him questionable for tonight, but his own words seemed to indicate that being right for the postseason is more important than risking a quick comeback. "I’m feeling better," said Chandler, who has sat out the last six games with what the team calls a bulging disk in his cervical spine. "It felt good to get on the court, but I’ve got some things I’ve got to work on. "I need to not go into a spasm whenever I’m in a vulnerable position, whether I’m reaching to block a shot or in a defensive stance. Right now, it’s still a little sore. Hopefully, [today] [I’ll] go through the shootaround and see from there. I can feel it a little bit, but I’m not worried about just a little pain. "It’s more so I don’t want to be back in a predicament where I come back and then I’m out for a week or so. When I’m back I want to be back."