Signed by Seattle as an undrafted rookie free agent following the 2019 NFL Draft.
Saw action in 41 games and started the final 20 games played for the Buckeyes until a lower leg injury in the regular season finale sidelined him for his final two games as a Buckeye. He earned third-team All-Big Ten Conference honors for his efforts and the line ranked third in the Big Ten in fewest sacks allowed in 2018, a season in which the offense had a school-record 561 passing attempts. Was a part of Ohio State teams that won a national championship over No. 2 Oregon in 2014, Big Ten Championships in 2014, 2017 and 2018, and bowl game wins over No. 1 Alabama (in the 2015 Sugar Bowl), No. 8 Notre Dame (2016 Fiesta Bowl), No. 8 USC (2018 Cotton Bowl) and No. 9 Washington (2019 Rose Bowl). Was a consensus four-star tackle for undefeated All Saints Episcopal team but had high national rankings as an offensive guard. Rivals rated Knox as its No. 2 guard prospect and Scout (No. 7), 247Sports (No. 10) and ESPN (No. 11) also had him highly ranked. Helped All Saints Episcopal to consecutive 11-0 seasons and Southwest Preparatory School championships. He graduated in December 2017 from Ohio State with his bachelor's degree in sport and industry.