Tomlin acknowledges that a rookie needs reps to prepare to play, so the Steelers hope Smith-Schuster's injury improves well before Sunday's game against the Green Bay Packers.
Smith-Schuster is second on the team in touchdown receptions (five) and receiving yards (568). His big social media presence and touchdown celebrations have made him a popular Steeler in his first year.
Practice time is crucial for rookies who might hit the proverbial wall.
"The seasons that [rookies] are used to are coming to a close -- they are getting ready for finals, they are transitioning to bowl prep," Tomlin said. "Guys like [T.J. Watt] and JuJu and others, they are moving into uncharted territory."
In other Steelers injury news, the team will watch safety Mike Mitchell (ankle) and tight end Vance McDonald (ankle) as they try to recover before Sunday. Both players missed the 40-17 win over the Tennessee Titans on Thursday.