Pickett went to the locker room for evaluation after taking a hit by linebacker Devin White on a play-action pass midway through the third quarter. Mitchell Trubisky replaced Pickett with Pittsburgh up 13-12.
The rookie's head injury comes a week after the NFL and NFLPA modified concussion protocols following their investigation into Dolphins quarterback Tua Tagovailoa's concussion evaluation on Sept. 25 against the Bills.
Pickett exited the game after going 11 for 18 for 67 yards and his first career touchdown pass, a six-yarder to running back Najee Harris.
Trubisky, who began the season as Pittsburgh's starter but was benched in favor of the rookie Pickett in Week 4, led the Steelers on four second-half drives, including a 71-yard TD march to extend their lead. After the Bucs pulled within two with 4:38 to go in the game, the veteran quarterback iced the game with three first downs on a 46-yard drive to run out the clock on Tampa Bay.
Trubisky finished 9-of-12 passing for 144 yards and a TD pass to Chase Claypool.
The Steelers (2-4) play at the Miami Dolphins next Sunday evening.