Prior to this, he played with Sale Sharks and Northampton Saints in Premiership Rugby and Pro14 side Connacht.

Mitchell made his professional debut for Sale Sharks against Worcester Warriors on 25 January 2014.

On 7 June 2017, it was announced that Mitchell, who qualifies to play for Ireland via his grandmother, had signed a two-year contract with Irish province Connacht.

[3] Mitchell joined Premiership Rugby side Northampton Saints on a short-term contract ahead of the 2019–20 season.

[4] At conclusion of his contract with Northampton he joined RFU Championship side Doncaster Knights.