After another injury plagued season, Mata'utia was able to break back into the Knights' NRL side in round 18 of the 2017 season, going on to play 4 NRL matches for the year and scoring two tries. On 23 November, it was announced that he would be retiring from the professional level of the game and joining the local Newcastle Rugby League, after being granted a release from the final year of the Knights contract. Mata'utia said after being released “The club has been great to me and I will miss everyone, but it is the right time for me to step away from the game at this level”.