Jenkins first played rugby at Long Ashton School, and would later represent local teams Mountain Ash and Newbridge.
On 22 November 1906, Jenkins turned out for Monmouthshire to face Glamorgan in a Welsh trial for the upcoming international between Wales and South Africa.
[7] Four new caps managed to break into the Welsh team, Jenkins, Dick Thomas of Mountain Ash, John Dyke of Penarth and Cardiff's Johnnie Williams.
At the trial, of the new caps, only Williams impressed, none of the other three players showed great ability, but were "distinctly superior to any of their uncapped rivals".
[11] In 1908, Jenkins was invited by fellow London Welsh teammate and friend, Arthur Harding, to join his Anglo-Welsh team on their 1908 tour of New Zealand and Australia.
[14] Although Jenkins severed all ties between himself and the club from 1919, his record at London Welsh remained impressive, spanning 12 years and 200 games.