Although Mills originally played for Mountain Ash,[2] he came to note as a rugby player when he represented first-class club Swansea, which he joined in 1892.

Despite this, the selectors kept faith with the team and in particular the forwards, which paid dividends the next season when Wales, under the captaincy of Arthur 'Monkey' Gould won the Triple Crown for the first time in their history.

Mills was reselected for the 1894 Home Nations Championship, but a mixture of poor pitch conditions and Welsh in-fighting resulted in two loses and just a single win.

At the end of the 1894 season, Mills is recorded playing at least one match for Glamorgan, alongside Swansea team-mate Billy Bancroft.

[3] The next season Mills had switched clubs from the Whites of Swansea to the Blues of Cardiff, but retained his position in the Welsh squad.