Treherbert not only joined the Northern Union, but with the addition of Barry and Aberdare, the six newly formed teams set up the Welsh League.
[4] A week later the club faced their first team from the Northern Leagues, a home tie with Halifax which Treherbert being outscored seven tries to two, losing 6-27.
More difficulties occurred when, in a 10-0 defeat by Merthyr Tydfil RLFC, two newly acquired players, Bob Williams and H. Harding, were prevented from playing after their joining forms had been 'destroyed'.
[6] After a further loss to Ebbw Vale and a draw with Barry,[4] Treherbert faced Merthyr Tydfil again, this time a Welsh League match.
To complicate matters further, the attendance figures at home matches were poor, last minute team changes were frequent and their club secretary, H.R.
[6] The only good news the club received was when one of their forwards, David Galloway was selected for the Wales national team, in a late 1909 away encounter with England.
Galloway did enough to impress as four months later he was reselected for the national team again, again against England, but this time played on home soil at Ebbw Vale's Bridge End Field.