Chauncey Billups is doing everything in his power to play again in the series, sooner than later. The Daily News has learned that Billups, who missed Tuesday's Game 2 against Boston with a strained left knee, had fluid removed from his knee and received a cortisone shot in an attempt to play in Game 3 tomorrow. The Knicks are calling Billups questionable and privately feel he will need at least one week to recover from the injury he sustained in the final two minutes of Sunday's Game 1 loss. "He's doing everything he can to get back out there," a Knicks official said. "This is killing him. He feels they would have won both games if he was out there at the end." An MRI of Billups' left knee confirmed a strained tendon. He could risk further injury by playing, but Billups is determined to get back on the court. By doing so, he could also jeopardize a $14 million contract option - the Knicks can pick it up or buy Billups out for $4 million. The team has five days after the conclusion of its season to determine Billups' future.