Hubbard intended on attending Notre Dame on a lacrosse scholarship before Urban Meyer showed up at Archbishop Moeller for a recruiting trip. Since that trip, the young man has added 70 pounds, transitioning from a safety that helped Moeller win back-to-back state titles to defensive end. Hubbard redshirted in 2013 as the team moved him again from linebacker to end as he continued to grow. He started for suspended starter Joey Bosa in the opener of the 2015 season, then came in as a reserve the rest of the season, earning Freshman All-American honors after posting 28 tackles, eight for loss, 6.5 sacks, an interception and a forced fumble. Once Bosa left to be the number three overall pick in the 2016 NFL Draft (San Diego), Hubbard had the starting spot all to himself. He was an honorable mention All-Big Ten selection in 2016, racking up 46 stops, eight for loss, 3.5 sacks, and two pass break-ups. League coaches named Hubbard second-team all-conference the following year, starting eight of 14 games played, creating 13.5 tackles for loss, seven sacks, and two forced fumbles. Hubbard was a first-team Academic All-American as a sophomore (3.61 GPA in Finance).