On Wednesday, Brown's absence was listed as a coaches' decision but when Thursday's practice report was released the sore knee was listed as the reason.
Brown is not expected to miss Sunday's season finale against the Cincinnati Bengals and his absence is viewed as precautionary similar to fellow wideout JuJu Schuster-Smith's absence last week ahead of the game against New Orleans.
Brown has been among the league's most prolific wideouts with 104 receptions, 1,297 yards and a league-leading 15 touchdowns. Last week, Brown finished with 14 receptions for 185 yards and two touchdowns.
While Brown was kept out of practice, the Steelers potentially received some good news when running back James Conner practiced for the second consecutive day. Conner has missed the last three contests with a high ankle sprain and said his condition is improving.
Conner has 12 rushing touchdowns on 201 carries for 909 yards. He also has 52 receptions for 467 yards and a touchdown.
The Steelers (8-6-1) have lost four of their past five games, and all four losses were by seven points or fewer. To reach the postseason, they must beat Cincinnati and rely on outside help.