BOSTON – While at the University of Louisville, Terry Rozier’s favorite subject was math.

It’s fitting when you consider how his play of late in the preseason has added up to what should be a prominent role off of Boston’s bench.

He certainly delivered a strong performance in Boston’s 113-96 preseason win over Philadelphia on Monday.

Rozier had a double-double of 15 points and 10 rebounds with six assists, a steal and a blocked shot.

But more important, Rozier had a command of the game at both ends of the floor that we’ve seen flashes of in the past, but rarely has the third-year guard been able to sustain that level of control consistently.

It’s all part of the work Rozier put in this summer in preparation for what he anticipates will be a breakout season.

Rozier appeared in just 39 games as a rookie during the 2015-2016 season, averaging just 1.8 points, 1.6 rebounds and 0.9 assists while shooting 27.4 percent from the field.

Last season he nearly doubled his stats in most categories, averaging 5.5 points, 3.1 rebounds and 1.8 assists while shooting 36.7 percent from the field while appearing in 74 games.

Rozier spent this summer working out in Cleveland, Los Angeles and Miami with pick-up games including former Celtics like Jeff Green and Kelly Olynyk in addition to All-Star talent such as Washington’s John Wall.

And those matchups combined with a stronger, more fit physique, has Rozier feeling ready to make his mark this season.

“I feel pretty confident,” he said. “I put in a lot of work this summer. I’m not second-guessing myself. I’m going out there and having fun.”

In a separate interview with NBC Sports Boston, Rozier reiterated how different things are for him heading into this season.

“Definitely. I just feel different,” Rozier told NBC Sports Boston. “This year is my first year that I feel I got a role and feeling comfortable, just out there. It felt so natural. I don’t have to think so much like I usually do. Once that settles in, it’s over.”