It took him about a week to get over the sadness and disbelief after being traded by the only franchise he had played for in his first 31 / 2 seasons in the NBA. Jeff Green didn't have much time to wallow after the Oklahoma City Thunder dealt him to the Boston Celtics at the trade deadline, because the task put before him — to back up two potential Hall of Famers in Paul Pierce and Ray Allen and help the league's most storied organization claim an 18th NBA championship — was daunting enough.

In the nearly two months since Green donned green, the former Georgetown star has had to adjust to being a backup after being a starter, to playing small forward after being used primarily at power forward, and to being a defensive specialist after being an occasional offensive threat.

"Those are big adjustments in a short period of time, on a team that's trying to win a title," Celtics Coach Doc Rivers said on Friday. "We're asking a lot. We knew that. And he's doing his best."

Green has overcome his initial confusion with the changes, and no longer feels overwhelmed, but he is still trying to find his way.

"It's been a whirlwind. Especially the beginning, coming to Boston, going to a new team, first time getting traded, going to a high-profile team, a lot of expectations. It was tough," Green said as the Celtics prepared to host the Miami Heat in Game 3 of their Eastern Conference semifinal series on Saturday at TD Garden. "When you're in a situation like I was in, you don't think stuff like that can happen. You look past it, like, 'That could never be me, I could never be in that position.' And when it happened, I was kind of shocked. It was tough, the first couple of days, to get over it. But eventually, I did."

When his season began in Oklahoma City, Green said the team had aspirations to make significant progress after losing a tough, six-game, first-round series against the Los Angeles Lakers. But when he arrived in Boston — where the Celtics have won a championship and reached the NBA Finals twice in the past three seasons — he knew right away that the goals are "much higher. It's different, coming from a situation where the goal is to make it out to the playoffs, get out of the first round. Here it's a championship or it's a fail."