"I'm highly concerned for our franchise and for Ben personally," Tomlin said in Orlando, Fla., where he's attending NFL meetings beginning Monday.
Tomlin told the NFL Network he didn't want to say too much about the situation, which police in Milledgeville, Ga., are still investigating. A 20-year-old female college student made the accusation against Roethlisberger, 28, this month.
"My concerns are many, but I think at this time it's kind of appropriate to watch these things and let these things run their course," Tomlin said. "I think it would be inappropriate for me to have strong feelings one way or another with the investigation being ongoing and so forth. Like everyone else, you watch these things unfold."
Roethlisberger has not been charged in the case. Defense attorney Ed Garland has maintained that the quarterback has not committed a crime.