Celtics center Kristaps Porzingis hopes to play Thursday against the Bulls. He left Boston’s win over Washington on Sunday with right heel pain. Charles Krupa/Associated Press

The Boston Celtics have been able to get plenty of rest and practice time in December since they didn’t advance in the NBA Cup. That’s helpful considering they are dealing with a few injuries, including to center Kristaps Porzingis.

Porzingis left the Celtics’ 112-98 win over the Wizards on Sunday with right heel pain. Porzingis said after the game he thought he would be ready when Boston faces Chicago on Thursday night. Celtics Coach Joe Mazzulla said Tuesday it didn’t appear the injury was serious.

“He’s getting better,” Mazzulla said. “He’s in the weight room right now. Go through some shooting and then we’ll just kind of see how he is day-to-day.”

Porzingis left the game Sunday in the first half. Initially, the team labeled him as questionable to return. The Celtics were in control throughout the game and didn’t need to push Porzingis back into action.

Porzingis missed the first month of the season after offseason surgery.

“I banged up my heel a little bit,” Porzingis told reporters in Washington. “I kept on playing. It was nothing major, honestly. More like a precautionary thing. It was pretty sensitive. I told the medical staff and they just pulled me out of the game. I don’t think it’s anything major.”

THE CELTICS ARE right near the one-third mark of their season and are among the best teams in the league at 21-5. Amid that start, Payton Pritchard has continued to be one of their biggest surprises, elevating his game to heights only he could see coming.

Pritchard is the early frontrunner for the NBA’s Sixth Man of the Year award. He’s averaging 16.5 points, 3.6 rebounds and 3.3 assists per game, and making a career-high 43.5% of his 3-pointers. But there’s one area Mazzulla pointed out that really helps elevate his game.

“One of his biggest strengths is he plays without an expectation,” Mazzulla said. “He doesn’t expect to get the ball. He doesn’t expect to have a play (called for him). He doesn’t expect to impact a game in this way. He just comes into every game very open-minded. He does a great job when he’s on the bench being aware of giving the game what it needs, whether it’s offensively, defensively or both. And when you play with that type of freedom, you’re able to impact the game in so many different ways.”

Mazzulla said Pritchard impacts the game differently on a nightly basis. He’s had two straight games posting a double-double, but in different ways. One night, it was 10 assists against the Pistons. He followed that with an 11-rebound game against the Wizards.

Pritchard, especially, has trusted the process with the Celtics. Just a few seasons ago, buried down the depth chart behind three capable point guards, the Oregon product wanted a trade for a larger opportunity. Instead, the team retained him. Now, Pritchard’s deal looks like one of the best contracts in the league. The Celtics inked him to a four-year, $30 million extension last season.

There’s still plenty of basketball left to be played, but it’s clear Pritchard has earned more shots and opportunities. But as Mazzulla pointed out, he doesn’t necessarily view it that way. That’s how Pritchard played in past seasons when minutes weren’t guaranteed. Now he’s brought that same mindset to every game he plays in the present.

“It’s not something I really think about,” Pritchard said of awards after Boston’s win over Detroit. “If I’m fortunate enough to win, that’s I guess a testament to the hard work I put in, and I think it just means that I helped this team coming off the bench and doing my job at a high level. It’s not something like if I don’t win or win, it’s not make-or-break it for me.”