For 24 minutes, it looked like Larry Bird, Kevin McHale and Robert Parish had walked through the door for the Celtics. The trio apparently came back disguised as Jeff Green who had 20 points by halftime. Then in the second half, it looked like the Celtics had Eric Montross, Jerome Moiso and Acie Earl as the cavalry. “They started to be more aggressive,” said Green, who shot 1-of-5 and scored six points in the second half to finish with 26. “When I caught the ball there were double teams. I didn’t run in transition as I did in the first half. I have to be more aggressive.” Well, it’s harder to be aggressive when the other team puts a bull’s-eye the size of Montana on your back. In the fourth quarter especially, the Knicks swarmed Green and forced him into four turnovers, three of them in the last 5:30. That’s what Celtics fans will remember of Green in Boston’s 85-78 Game 1 defeat, not his 7-of-10 first half shooting, including 3-of-3 on 3-pointers.