[3] In 2015, Barnett graduated to Canberra's New South Wales Cup team, Mount Pritchard Mounties.

[8] In November, after Barnett's management discovered his new Canberra contract for the next two seasons hadn't been lodged with the NRL, he opted to instead attempt to sign a more lucrative deal with the Gold Coast Titans.

[17] In round 11 against the Sydney Roosters, Barnett kicked two goals, with one from the sideline, after regular kicker Kalyn Ponga went off the field with an injury.

[20] Barnett played 24 games for Newcastle in the 2021 NRL season including the club's elimination finals loss against Parramatta.

[23] Barnett had pleaded guilty and claimed the contact was careless, however, it was found to be reckless in nature, with a six match suspension handed down in relation to the incident.

[27] Barnett played 15 games for the New Zealand Warriors in the 2023 NRL season as the club finished 4th on the table and qualified for the finals.