In the holidays, he played club rugby for Newport, and he was part of the team that defeated the touring South African side of 1912–1913.

[1] Although Geen was a decent cricketer, keeping wicket for Oxford University Authentics and Monmouthshire in the Minor Counties Championship between 1909 and 1912,[2] his rugby playing was more notable.

A similar passage of play again saw Poulton put Geen through for a try, but he dropped the ball after crossing the line while trying to get closer to the posts.

[6][7] A couple of days before the Varsity Match, talk in the press had been of Geen's likely selection for England for the forthcoming Home Nations Championship.

[8] Geen and Poulton, who together were considered the scoring force of the Oxford team, were both selected to play for England in the second trial match against The North in Leeds.

[14] However, Poulton suffered a hamstring injury early on and his replacement Eric Thomas, a forward, lacked the speed and skills to combine effectively with Geen.

[16][17] He was described by Tommy Vile's biographer Philip J Grant as looking "the promising player in Wales"; and scored 10 tries and a dropped goal in 14 games for the Monmouthshire club.

Whereas Newport, according to "Dromio" (W J Townsend Collins) writing in the Argus, had been poor in attack in their previous three encounters and weak in defence in the last two.

The ball was then worked back to Fred Birt, standing within range in front of the posts, and he kicked a drop-goal, putting the home side 4–0 ahead at the break.

In the second half, the Springboks repeatedly attacked but the Newport defence kept them from crossing the line, although a break from Dick Luyt, the South African centre, left Douglas Morkel to score under the posts.

[21] Newport was one of only three teams to beat the Springboks on the tour and Geen played his part, bringing down Johan Stegmann when he was within sight of the try line.

Only two backs were to be retained, Bobby Williams, the fullback, and Billy Geen, deemed the outstanding threequarter against England, moving from wing to centre.

[28] However, on the Wednesday preceding the encounter in Edinburgh, Geen withdrew after a training session due to an ongoing shoulder injury, and his place on the team was taken by Willie Watts.

[29] His final game for Wales was on 8 March 1913 against Ireland, when he showed "brilliance and judgment" (according to Townsend Collins) helping to create two tries towards a Welsh 16–13 victory.

[16][30] Geen was selected to play centre for the first match of the 1914 Home Nations against England at Twickenham but was forced to withdraw due to injury.

[35] Despite missing the Swansea game two days later, Geen returned to the Barbarians squad to face Cheltenham, which ended in an 8–3 victory for the tourists.

Despite this, Edgar Mobbs organised two Barbarians matches against Leicester in early 1915 to aid recruiting and to raise charity funds.

[46] Major John Hope wrote: "Geen fought gloriously, and was last seen alive leading his platoon in a charge after being for hours subjected to liquid fire and every device the Germans could bring to bear to break through.