Roethlisberger, who led the Steelers to two Super Bowl victories the last four seasons, had some problem walking when he left the team's training complex but his knee was not bandaged.
Roethlisberger left the field during the Steelers' morning practice after the problem developed, and was examined along the sideline by trainer John Norwig. Roethlisberger apparently did not need any medical attention and began stretching his leg before practice ended.
Neither Roethlisberger nor coach Mike Tomlin discussed Roethlisberger's problem, and Tomlin said there would be no update.
Roethlisberger is scheduled to play golf Friday in an event at Bethpage Black, the site of this month's U.S. Open.