Trevarthen was a part of the Ohinemuri Rifle Volunteers and played a rugby match for them in 1908 at the start of the season against Paeroa.
[5] After returning from the war he played a preseason match for Ohinemuri Rifle Volunteers before moving to Auckland and joining the Grafton club.
In 1907 Trevarthen was selected to be a part of the professional All Blacks tour of Australia and Great Britain, as a forward.
Trevarthen played in the first ever trans-Tasman test which was the début match of the Australia national rugby league team.
Trevarthen then accepted a contract to go join Huddersfield alongside New Zealanders Edgar Wrigley and Conrad Byrne.