Roberson, who missed most of last season with a broken leg, played the entire first quarter before exiting the game with bruised ribs. Roberson was 3-of-6 for 71 yards and two touchdowns in his quarter of action.
"He took a shot and was a little gimpy, and that's why I went to the other guy [Nate Sudfeld]," said Indiana coach Kevin Wilson. "And then the score went to 42 like that, and we just went with Cam [Coffman] and Nate from there.
"It's not an injury deal. He was good to go. He said he could play the second half, but with the way the score was, we just didn't go back to him."
Wide receiver Shane Wynn also left Thursday's game with an injury after taking a cheap shot hit on a punt return.
Wynn, who recorded three touchdowns in his limited time on the field, left in the third quarter and did not return.
"Shane will be fine," Wilson said.
Added wide receiver Kofi Hughes: "He's good. He's already joking around, talking about playing Fifa and stuff. So he's good."