BOSTON - We knew going into the 2015-16 season that the Boston Celtics were a deep team.

We knew that Brad Stevens wasn't going to be shy when it came to dipping into his bench early and often.

We knew that Jared Sullinger was at the end of the rotation heading into Wednesday, too.

Well . . . two out of three ain't bad.

Sullinger is alive and well, folks. He may or may not have lost any weight over the offseason, but he did dye his hair.

And on Wednesday, he was the first Celtics player off the bench for Brad Stevens' bunch.

Tyler Zeller was having trouble containing 2015 3rd overall pick Jahlil Okafor, and shortly after Zeller picked up his second foul, Stevens made the move.

Steven had liked what he had seen from Sullinger in the teams' final preseason matchup last week, and thought it was worth going back to him again.

"I thought he was good one-on-one guarding him," Stevens said of Sullinger's defense on Okafor last week. "Sometimes guys do a great job and the guy just gets to cooking and you gotta change something up. And that's what happened. So he went in pretty early and thought he did a good job."

With depth on Boston's side, Stevens can look to his bench quickly. If it's working - and in this case it was because Okafor's scoring binge stopped - he'll stick with it. For that reason, Sullinger started the third quarter, with Zeller on the bench until the later stages of the fourth quarter.

"Everybody's gotta be ready," Stevens said. "I told Tyler at halftime, 'This may not be your night but there's going to be plenty of them.' So just kind of stay the course. I'm glad to see [Zeller] finished well and he actually defended really well I thought at the end of the game, too."

But credit is due to Sullinger, who many at least outside of the organization were down on heading into the season. He wasn't down on himself, either.

"You always gotta be ready. You never know," Sullinger said. "But at the same time we kind of prepared for something like that. Just because you don't do it in preseason, that doesn't make it final. We just came out, we played hard and I'm just glad we got the kick-start we needed."

Okafor scored two points in the first quarter with Sullinger in the game, and two more early in the second quarter before Sullinger was taken out. But that's a far cry from the quick eight he scored early in the first quarter. Okafor scored just two points from the free throw line in the third quarter before picking things back up in the fourth with 10 more points. He finished with 26 points, seven rebounds and eight turnovers over 35 minutes in his debut.

Sullinger had 12 points, seven rebounds, and one turnover in 21 minutes.

"Just try to bump him early," Sullinger said of defending Okafor. "Try to gas him out early and meet him at the free throw line. Couldn't let him get deep position and some of the shots he was hitting it was just like, man, it was his night. I knew for a fact that those shots weren't going to beat us and just made it as tough as possible."

There were high expectations surrounding Sullinger at the beginning of last season, as he was a starter on opening night. This year is different. Offseason additions led to a preseason in which Sullinger wasn't seen as often. But maybe that's not such a bad thing.

"Y'all shocked?" Sullinger asked reporters of his performance. "It's preseason. It's preseason for a reason. None of them stats really matter. Last year was the opposite. I was shooting the ball extremely hot and then after the regular season it kind of dwindled down. Hopefully it's the opposite this year."

It's only been one game, but we're already seeing that while roles may change on a game-by-game basis, you really can't count anybody out of this Celtics rotation.