KISSIMMEE, Fla. -- Brett Brown understands the NBA playoffs are all about adjustments.

Not making the proper ones could lead the 76ers into a 2-0 hole by Wednesday night. They talked about finding ways to get Joel Embiid the ball and cutting down turnovers. But another big adjustment could be in the Sixers’ starting lineup.

How will Brown counter the Celtics having guard Marcus Smart start in place of injured forward Gordon Hayward in Game 2 of the first-round series?

Hayward is expected to miss four weeks after suffering a Grade III right ankle sprain in Monday night’s Game 1 victory over the Sixers. Brown said before Tuesday’s practice that Hayward’s replacement in the Celtics lineup could influence his starting lineup.

The 6-foot-3 Smart will join Kemba Walker (6-foot), Jaylen Brown (6-6), Jayson Tatum (6-8) and Daniel Theis (6-8) in what was an already small but athletic starting lineup.

The Sixers can stick with their towering frontcourt of Tobias Harris (6-9), Embiid (7-2), and Al Horford (6-10). They could also opt to start rookie Matisse Thybulle (6-5) at small forward and move Harris to power forward. Horford would come off the bench.

“It’s all on the table,” Brown said when asked about going with a smaller lineup. “I’m very influenced, by and large, by trying to match minutes.”

Thybulle did a solid job of defending an otherwise unstoppable Tatum in Game 1. Tatum scored four points on 2-for-9 shooting, including going 0-for-1 from three-point land, while being guarded by the rookie. Thybulle blocked the three-point attempt. Tatum scored 28 points on 8-for-12 shooting, including 2-of-4 on threes, against the other Sixers.

Brown mirrored the court time of Josh Richardson (37 minutes, 11 seconds) and Thybulle (32:41) to Walker (34:42) and Tatum (41:27).

“I thought Matisse did a great job,” Brown said. “I thought J-Rich was J-Rich. We need them to be elite defenders on those two great scorers. So anything’s on the table once we learn this Gordon Hayward news.”

Hayward’s right foot landed awkwardly on the foot of Theis after battling for a defensive rebound in the fourth quarter. Hayward didn’t return and left the arena on crutches and in a walking boot.

“I feel for him more than anything else,” Boston coach Brad Stevens said Tuesday. “It’s our job to make up for all the great things he does by committee.”

Hayward had 12 points and four steals in 34:27 on Monday. He averaged 17.5 points while shooting 38.3% from long range during the regular season.

Smart averaged career-highs of 12.9 points and 4.9 assists in 60 games this season with 40 starts. He’s also a tough player who doesn’t back down from anyone.

“Role is different,” Smart said. “Differentiate starting, coming off the bench. But energy-wise is the same. I have to bring the same energy.”

He knows there will be more emphasis on Tatum, Jaylen Brown, and Walker as he joins the lineup. He’ll have to be ready to knock down shots as opposed to easing into the game off the bench.

“In that aspect it changes,” Smart said. “But I still got to be the defensive pest that I am, the best defensive player in the league that I am, and continue to be there for my team.”