After missing out on selection for Vic Country in the 2014 AFL Under 18 Championships, McDonald played nineteen matches for the North Ballarat Rebels in the TAC Cup, with the second half to his season raising his draft chances. His strong season was acknowledged with awards and accolades including, winning the Adam Goodes trophy for the club best and fairest, the TAC Cup coaches award, and he was named as the centre half-back in the TAC Cup team of the year.
AFL career
Predicted to be drafted inside the top thirty in the 2014 national draft, McDonald was drafted by with their fifth selection and fifty-third overall. He spent the start of 2015 playing for Melbourne's Victorian Football Leagueaffiliate team, the Casey Scorpions, in the VFL Development League, he was then promoted to the senior VFL team in round three, playing there for most of 2015. He made his AFL debut in the fifty-four point loss against at Domain Stadium in round 22. He played in his first win the next week and in the final match of the season, when Melbourne defeated 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. After playing in the first and final match of the 2016 NAB Challenge against and respectively, McDonald started the season playing in the AFL when he played in the opening round match against Greater Western Sydney in the two point win at the Melbourne Cricket Ground. During the match, he suffered an ankle injury which forced him to miss the next week. Playing for Casey, he received a concussion which saw him miss further football. He returned to the senior side in the sixty-three point win against the at the Melbourne Cricket Ground in round nine. 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. Despite not missing another match, he did, however, injure his ankle a further two times during the season, in the round 16 match against Fremantle and the round 18 match against. After finding consistency in the back-line, he was awarded the round 21 nomination for the AFL Rising Star in the forty-point win against Port Adelaide at Adelaide Oval, where he recorded twenty-three disposals, nine marks, and five rebound-50s. In August, he signed a two-year contract, tying him to the club until the end of the 2018 season.
