Rookie running back James Conner (shoulder) and cornerback Senquez Golson (hamstring, according to ESPN NFL Insider Adam Schefter) were evaluated at a Pittsburgh hospital for injuries suffered during Sunday's practice.
Conner is a third-round pick and a popular NFL player for beating cancer while a standout at Pitt.
"That evaluation has happened," coach Mike Tomlin said. "I don't have that information yet. No update on when they'll return. When I get it, you get it."
Golson hasn't played an NFL down due to various injuries since he entered the league as a second-round pick in 2015. He left Sunday's practice on a cart.
"The off-day probably comes at an appropriate time," said Tomlin, whose team is off Tuesday. "We've gotten [a] lot out of these guys the last few days. The effort has been extraordinary. That's to be expected when you're doing what we're trying to do here, which is to develop into a world-championship-caliber group."