Mitchell was selected by Port Adelaide with the 5th selection in the 2013 Rookie Draft.[4] He was elevated from the Rookie List due to Nick Salter being placed on the long-term injury list,[5] he made his debut in round 1 against Melbourne at the MCG as a substitute in the fourth quarter. He scored his first AFL goal against GWS in Round 2.
In 2015, he was promoted to Port's senior list.[6] He was delisted by the club in October,[7] but was re-drafted in the 2016 rookie draft.[8]
Mitchell was delisted again at the conclusion of the 2016 season.[9] Following his delisting, Mitchell took a year off to go travelling, returning to play for Claremont in 2018.[10]