The wide receiver could miss more time beyond that.
ProFootballTalk.com cited "a source with knowledge of the situation" in reporting Saturday that Brown will miss "a few games" with the ankle injury suffered during Week 9's win over the New York Giants.
NFL.com and NFL Network's Albert Breer later confirmed the report, per a source who's spoken with the player.
Brown is a consistent performer who emerged last season as a favorite target of Ben Roethlisberger. In eight games this season, Brown has 42 receptions for 499 yards and a touchdown.
Running back Isaac Redman, who rushed for a career-high 147 yards in last week's 24-20 win over the New York Giants, said Saturday he will start in Mendenhall's place. Rookie running back/return specialist Chris Rainey will play despite cracked ribs and running back Jonathan Dwyer -- who missed the Giants game with a right quadriceps injury -- is also expected to play.
The Associated Press contributed to this report
Follow Dan Hanzus on Twitter @danhanzus.