Harvin was hurt on a 21-yard completion. It was not clear from the replay how the injury occurred.
He was helped off the field with a member of the training staff under each arm.
The team announced that his return was questionable. But Harvin was back in the second quarter and showed no problems on a 15-yard slant pass.
Harvin is the Vikings' No. 1 receiver, with 25 catches and three touchdowns in Minnesota's first six games.