[3] He averaged 20.8 points and 8.2 rebounds per game as a junior, won the 2018 Illinois Mr. Basketball award,[4] shared the 2018 St. Louis Post Dispatch Player of the Year with Courtney Ramey,[5] and won the Illinois 4A class state championship.

On October 1, 2018, Liddell committed to playing college basketball for Ohio State over scholarship offers from teams such as Illinois, Missouri, and Wisconsin.

[11] During the early parts of his sophomore season, he contracted mononucleosis, which led to Liddell being out for several games.

[10] After Ohio State's Round of 64 loss to Oral Roberts, Liddell received threats from basketball fans via social media.

On March 25, 2022, Liddell declared for the 2022 NBA draft, forgoing his remaining college eligibility.

During an NBA Summer League game against the Atlanta Hawks on July 11, 2022, Liddell suffered a torn ACL.