Roethlisberger told reporters he doesn't know the nature of the injury, but he said he won't miss time.
"We will find out soon, hopefully," Roethlisberger said. "You're always worried about being hurt, but I'll be out there next week."
The Steelers next play the Kansas City Chiefs in Sunday's divisional round.
Roethlisberger suffered an injury on his final play of the game. With 4 minutes, 34 seconds left in the fourth quarter and the Steelers up 30-12, Roethlisberger attempted a pass while on the move. The ball was intercepted by cornerback Xavien Howard, and Roethlisberger was slow to get up. The Steelers had taken running back Le'Veon Bell out of the game at that point.
A golf cart transported Roethlisberger through the Steelers' tunnel after his media session.
When asked whether he was surprised he was still in the game, Roethlisberger said he was not.
"I love being out there with the guys," he said.
Roethlisberger finished 13-of-18 passing for 197 yards, 2 touchdowns and 2 interceptions. He completed his first 11 passes.
Steelers coach Mike Tomlin was not asked about a Roethlisberger injury during his news conference availability, but Roethlisberger's condition was not known at the time, and Tomlin didn't list Roethlisberger among injured Steelers, as is customary for a postgame Tomlin news conference.