The departure of right back Moses Odubajo on the eve of the 2015–16 season and injuries in midfield saw McCormack reinstated in the team. His ever-present status ended in early December 2015, due to groin and calf injuries. McCormack finally returned to the team for a West London derby versus Queens Park Rangers on 12 March 2016 and he played the full 90 minutes of the 3–0 defeat. After six further starts, the option to extend his contract for a further year was triggered. He finished the 2015–16 season with 29 appearances.