After missing out on selection for Vic Country in the 2014 AFL Under 18 Championships,[1] McDonald played nineteen matches for the North Ballarat Rebels in the TAC Cup,[2] with the second half to his season raising his draft chances.

He made his AFL debut in the fifty-four point loss against Fremantle at Domain Stadium in round 22.

[10] He played in his first win the next week and in the final match of the season, when Melbourne defeated Greater Western Sydney by twenty-six points at Etihad Stadium, which was also the club's first win at the stadium since 2007, ending a twenty-two match losing streak.

[16] He returned to the senior side in the sixty-three point win against the Brisbane Lions at the Melbourne Cricket Ground in round nine.

[17] With the club focusing on youth, he maintained a spot in the seniors for the remainder of the season, which saw him play as the second key back behind his brother, Tom.

[22] After training with the Carlton Football Club ahead of the 2021 AFL season, McDonald was added to the Blues' rookie list as a preseason supplemental selection.