Nizialek was signed to the Steelers' practice squad Saturday and then elevated to the active roster, Brooke Pryor of ESPN.com reports.
Nizialek was released by the Falcons on Tuesday, Tori McElhaney of the Falcons' official site reports.
Nizialek (hamstring) has been designated to return from injured reserve Wednesday, Aaron Wilson of Sportstalk 790 Houston reports.
Nizialek (hamstring) was placed on the injured reserved list Tuesday, Aaron Wilson of Sportstalk 790 Houston reports.
Nizialek suffered a hamstring injury during Sunday's loss to Washington, Josh Kendall of The Athletic reports.
The Falcons released Nizialek (undisclosed) from the practice squad Thursday, Darren McFadden of the team's official site reports.
Nizialek (undisclosed) has been given an injury settlement by the Ravens, per the league's official transactions log.