Ott was injured during a second-half punt by the Illini and spent the fourth quarter on crutches on the Hawkeyes sideline.
A second-team All-Big Ten pick in 2014, Ott has been one of the top pass-rushers in the Big Ten this season and recorded his fifth sack of the year in Saturday's game. He has also forced three fumbles.
Iowa (6-0, 2-0 Big Ten) plays at No. 13 Northwestern (5-1, 1-1) next week.