By Brian Robb, CBS Boston

BOSTON (CBS) – Brad Stevens has had to mix and match his lineups with an ever-changing roster for the vast majority of the 2014-15 season.

Thus, it’s somewhat fitting that the Celtics head coach will have to deal with one more twist to the team’s rotation in the final two weeks of the regular season, thanks to Jared Sullinger’s surprise return on Friday night.

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The third-year forward was supposed to be sidelined for the season after suffering a stress fracture in his left foot on Feb. 11. However, after seven speedy weeks of healing and rehab, the big man was cleared to play by team doctors.

“I just assumed he was done for the year,” Stevens said on Friday. “I knew that he was getting better; the reports that I was getting was that he was getting better. But he was cleared. I think that [team doctor Brian McKeon] even came back and said, ‘His foot looks absolutely fantastic.’ He didn’t have any hesitation on clearing him. He feels good about it. He’s not at any additional risk or anything like that. It’s not a rash decision. He’s healthy. If he’s healthy, he should be available to play.”

Sullinger’s return to the court in Friday’s 110-101 loss to the Milwaukee Bucks was brief and uneventful, as anticipated. The one-time starting power forward playing grabbed a rebound and missed two shots in just three minutes of action. A lack of practice time with his teammates, along with a lack of conditioning has made Stevens leery of using Sullinger much in the interim.

“He hasn’t played or practiced with these guys,” Stevens noted. “He is physically great, he has worked hard in all the things that he’s needed to do and been able to do. But it’s not the same as playing. And it’s not the same as running up and down the court and playing. The way we’re looking at it, he’s available if needed this weekend, then we’ll evaluate after that.”

The 23-year-old understands those limitations, but was pleased he was able to make it through his first on-court action in two months without any setbacks.

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“I felt good. Just a little late on things, but felt good overall,” Sullinger said after the game, before adding how his rhythm was a bit off. “I just thought out there like whom am I playing with almost; kind of awkward. Just half a second late [on everything].”

Sullinger will get a chance to regain some of that rhythm after tonight’s game in Toronto. Boston will have three days off before their next contest on Wednesday in Detroit, giving Sullinger some value practice time with his new teammates.

With the Celtics trailing in the Eastern Conference race for one of the final couple postseason spots, Stevens will have to tread carefully. Boston can’t afford to lose crucial games while Sullinger gets comfortable on the court and potentially disrupts the team’s second unit. Isaiah Thomas, Luigi Datome, and Jonas Jerebko all had not played in a game with Sullinger before Friday night.

“He hasn’t played,” Stevens noted. “It does affect your rotation a little bit when you put a new person in, and it’s not as much an emotional thing as it is you’re used to playing a certain amount, or you’re used to a routine, or you’re used to playing with a group. We’ll see how that affects other guys as well.”

Whether or not the 6-foot-9 forward makes any kind of real impact in his return remains to be seen, but his teammates appreciate the dedication he has shown in returning quickly from his injury.

“We love having him,” Kelly Olynyk said. “We want him out there with us, fighting with us for the last [six] games of the season trying to make the playoffs.”

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Brian Robb covers the Celtics for CBS Boston and contributes to NBA.com, among other media outlets. You can follow him on Twitter @CelticsHub.