Boston’s Jaylen Brown is dealing with adductor tightness and could be out of the lineup for at least a week. Michael Dwyer/Associated Press

NEW YORK — The Celtics were shorthanded Thursday night against the Nets, as Jaylen Brown was downgraded to out because of adductor tightness.

Boston Coach Joe Mazzulla said he doesn’t expect it to be a long-term absence, but it could keep Brown out for a “week or so.”

“I’m not sure what the timeline is,” Mazzulla said. “I know he tried to give it a go today, and wasn’t able to do it. We’ll know more the next couple days, see how he responds.”

Brown said after Wednesday’s win over the Pelicans that he tweaked his groin, which is why he was initially questionable on the injury report. Brown put up a season-high 41 points in arguably his best game of the season as he continuously put pressure on the Pelicans. He was crucial in the Celtics extending their winning streak to four games.

With Brown out, expect the Celtics to spread out his minutes to Malcolm Brogdon, Derrick White and perhaps Payton Pritchard. The Celtics were also without Al Horford, as he doesn’t play the second game of back-to-backs. That means more playing time for Luke Kornet and potentially Blake Griffin.

Robert Williams III (left knee injury rehabilitation) was back in the lineup after sitting out Wednesday’s game for precautionary reasons. Marcus Smart also returned after a two-game absence because of a left knee contusion.

JAYSON TATUM is tracking toward being named an All-Star starter for the first time in his career.

In the latest round of All-Star Game fan voting released on Thursday, Tatum (3,281,124 votes) moved ahead of 76ers big man Joel Embiid (3,248,733) for third among Eastern Conference front-court players. Tatum trails Brooklyn’s Kevin Durant (4,509,238) and Milwaukee’s Giannis Antetekounmpo (4,467,306).

Entering play on Thursday, Tatum was averaging a career-best 30.8 points and was second in the NBA in total scoring with 1,233 points.

Fan voting makes up 50 percent of the vote that determines All-Star starters, with current players and a media panel accounting for 25% each. The next fan voting update is on Jan. 19 and voting will conclude on Jan. 21. All-Star starters will be announced on Jan. 26 for the game that will be played Feb. 19 in Salt Lake City.

Brown faces longer odds of becoming an All-Star starter, but is well-positioned to become a second-time All-Star. He remained fourth among Eastern Conference guards, but closed the gap on Philadelphia’s James Harden, who he trails by 58,707 votes. Brown also trails Brooklyn’s Kyrie Irving and Cleveland’s Donovan Mitchell in fan voting.