Aberdare born winger David “Dai” Nicholas was capped by Wales at schoolboy level in 1912 and he was given trials by Merthyr Town but due to World War I he was recruited by the Royal Navy. Towards the end of the War he played several games as an amateur for Swansea Town before turning professional with Merthyr Town making his Football League debut in their inaugural Football League fixture against Crystal Palace in August 1920.
He scored twice in 52 games for Merthyr before he joined Stoke in April 1922, helping them to promotion to the First Division that spring, where he was described as a ‘speedy winger’ who performed well on the wing for Stoke, before becoming homesick in 1924, and after 4 goals in 57 appearances for The Potters he moved back to Swansea Town in December 1924 via a brief spell at non league Aberavon Athletic and also became a teacher in his native Aberdare. He continued to play for Swansea until April 1930, winning the Third Division (South) Championship with them in his first season and scoring 16 goals in 166 appearances before retirement.
He was first capped for Wales in a 2-0 defeat against Scotland at Love Street, St Mirren in March 1923 and won 2 more Welsh caps through to April 1927, when he played in a 2-2 draw against Ireland at Ninian Park, Cardiff.