Celtics coach Ime Udoka offered an update on Monday and told reporters Brown will remain sidelined for one to two weeks because of the issue.
It's an unfortunate blow for a Celtics team that won two straight before Saturday's result. Boston sits at 4-6 overall heading into Wednesday's home game against the 6-5 Toronto Raptors. Center Al Horford reacted to the news and, per the club's Twitter account, said he and his teammates will have to "rally around" this setback.
"This is going to give opportunities for some of our other guys to step in and contribute a little more," Horford added.
According to ESPN stats, Brown leads the Celtics in scoring, averaging 25.6 points per contest. Earlier on Monday, Brown was linked with a potential move to the Philadelphia 76ers that would result in Boston acquiring All-Star guard Ben Simmons, who requested a trade away from that organization ahead of the campaign and who has told the Sixers he isn't "mentally ready" to play.
A report emerged Friday that the 76ers have resumed fining Simmons for missing games and other team-related activities.