Brown was ruled inactive for Sunday's pivotal game against the Cincinnati Bengals due to a knee injury that kept him from practicing all week.
Pittsburgh (8-6-1) needs to beat Cincinnati and get help in order to reach the playoffs for the fifth straight season.
A win or a tie against the Bengals coupled with a loss by the Baltimore Ravens against the Cleveland Browns would give Pittsburgh the AFC North title and a playoff spot. The Steelers can also qualify with the more unlikely scenario of beating the Bengals and Indianapolis playing to a tie with Tennessee on Sunday night.
Brown was listed as questionable for the season finale after missing practice on Friday to undergo tests on the knee. He also sat out Thursday but the Steelers described his absence as being for "precautionary" reasons.
Brown will finish his ninth season with 104 passes for 1,297 yards and 15 touchdowns. He finished this season with five 100-yard games, including 185 yards on 14 catches in last week's loss at New Orleans.
While Brown was declared inactive for the first time this season, the Steelers received some good news concerning running back James Conner. Conner was ruled active after missing the previous three games with a high ankle sprain and during the practices leading up to Sunday, the second-year running back said his condition was improving.
Conner has 12 rushing touchdowns on 201 carries for 909 yards. He also has 52 receptions for 467 yards and a touchdown.