The Celtics welcomed Jeff Green to the 2012-13 regular season with open arms last night. His mates were more than pleased to see him make his mark with 12 points and several pounds of assertiveness. Coming off a year lost to heart surgery, Green has stepped gingerly after a strong preseason. But in the 96-92 win over the Bucks, he came back from a shaky first half to spur the comeback. The best evidence of the change in the 6-foot-9 forward may have been when he missed on a driving dunk while being fouled four minutes into the last period. He made the two free throws as the C's pushed back. "I told Jeff to start going to the basket a little more," said Kevin Garnett. "He hasn't been in the best rhythm, we all know that. "I felt like after the dunk (attempt), he was a different player. He was going to the hole. He was rebounding with force. "You know, Jeff's a really, really nice guy, and some nights, you know, you've just got to be an (expletive). You've got to be .?.?. I can't really say what I want to say, but he's got to be that. And I felt like after the dunk he was aggressive. He was gritty Jeff, and when he's like that he's hard to stop. He's really hard to stop."