"We just collided and I guess he stepped on my foot and he fell on my leg," Tatum told reporters after the game. "But (I) should be alright. We'll see after tomorrow. I was able to walk off the court by myself, so that's a good sign. I hope (Jaylen's) alright."
Head coach Brad Stevens said he didn't have any updates on either player but that neither initially appeared to have any swelling around their legs.
Tatum has averaged 26.4 points, 7.5 rebounds and 4.4 assists through 57 games this season, earning his second All-Star nod in as many years, though he has been largely hindered by illness and injuries in his fourth NBA season.
Tatum missed five games in January after testing positive for COVID-19, and he said in February he was still feeling the effects of the virus, per ESPN's Tim Bontemps.
In addition to his stint in the NBA's health and safety protocols, he was also out in late March with a non-COVID-related illness. The Duke product landed on the injured list again and missed the April 27 game against the Oklahoma City Thunder due to an injury to his left ankle.
Brown, meanwhile, is enjoying a career year. He's averaging 24.8 points, 5.9 rebounds and 3.4 assists while setting personal bests in field-goal percentage (48.9) and three-point percentage (40.3).
The importance of Tatum and Brown together largely goes without saying. The Celtics are a worse team without one of the two, and their collective absence would be a major problem for Stevens as the team looks to climb into the top six in the Eastern Conference. As things stand, the Celtics would be stuck in the play-in tournament.