Then again, Smith could be ready to play.
Smith could be seen in a walking boot when he reemerged from the tunnel of the stadium.
"He's going to be sore," Harbaugh said of Smith. "He's going to be working through that soreness."
Despite leaving with an injury, Smith finished with 125 rushing yards on 16 carries, including a highlight reel 60-yard scamper for touchdown in the second quarter.
Asked to be more specific about Smith, whether or not the junior tailback is questionable or otherwise against Maryland, Harbaugh again remained mum.
"I don't think we have to do that in college football, do we?" Harbaugh asked.
"He's got something he's working through, added Harbaugh.
Should Smith not be able to go, Michigan would turn to a full shelf of running backs that could step in, including the Wolverines second leading rusher in Ty Isaac, Derrick Green, Ross Douglas or Drake Johnson.
Although it appears Isaac is Michigan's No. 2 tailback and likely to get the start if Smith is in fact out, Harbaugh says the competition is ongoing.
"Right now all of our running backs would like to carry the ball more and they're stating their case every time they get the ball," Harbaugh said. "They've been hungry for those reps."
"Two things, number one is I'd love to have that information from the opposition each week," Harbaugh added. "Who's going to start, what role are they going to be in, how are they going to use him, what will they be effective at? We don't get that information so why would we be in a position to give that information."