Jason Bay will not spend his winter in rehabilitation, as he did last year. Doctors confirmed yesterday that the Pirates' left fielder has nothing more than tendinitis in the patella tendon of his right knee, matching their original diagnosis with an MRI taken at Allegheny General Hospital. There was no structural damage, nothing that will require anything more than rest to heal. He was cleared yesterday to pinch-hit after a seamless batting practice, but it likely will be another day or two until he rejoins the lineup. "It's basically a matter of just getting it to relax a little," Bay said. "And that's a big relief compared to last year."