Tomlin took to Twitter to thank those who showed concern for his well-being.
A Steelers spokesperson said "members of the coaching staff and personnel were sent home last week after a couple positives came about," according to Brooke Pryor of ESPN.
During the regular season, the Steelers and Tomlin were reportedly fined $250,000 and $100,000 for mask violations, respectively.
The 48-year-old coach helped Pittsburgh win the AFC North with a 12-4 record in 2020. The Steelers were eliminated by the Cleveland Browns in the wild-card round.
Pittsburgh is set to begin a busy offseason, which includes contract negotiations that will determine the future of longtime quarterback Ben Roethlisberger.