Embiid initially was listed as doubtful for Tuesday's game against the Clippers because of a left knee contusion, but Brown confirmed that the 7-footer would miss the contest because of a left knee contusion.
"We're gonna be without him tomorrow, and in Milwaukee, and we'll go from there," Brown told reporters.
Embiid did not practice Monday, according to the team. He will not play Wednesday against the Bucks as part of the Sixers' regular rest plan for him.
Embiid suffered the injury Friday against Portland and did not play in the fourth quarter of Philadelphia's 93-92 victory that night. The Sixers announced that a precautionary MRI showed no significant damage in his left knee, and held him out of Saturday's game against Atlanta.
The Sixers also announced that Jahlil Okafor (knee soreness) was limited at practice Monday but is considered probable against the Clippers.