After representing Wales Youth Rugby Union as number 8 and captain in 1960, he was 'lured north' to play rugby league for Doncaster for the sum of £1000, enough to buy several houses in his home village at that time. At 6'2" and 17 stones, his dynamic skills, aggressive defence and size caught the eye of Warrington, who paid Doncaster £6000 just a few months later to sign him. He made his début for Warrington on Saturday 21 October 1961, Warrington converted him from a to a hard running ball distributor playing as a or. Whilst at Warrington, he was picked as captain of the Great Britain Under-24 team, and he played his last match for Warrington on Saturday 8 February 1964. He then moved onto St. Helens starring in one of the all-time great packs alongside legends such as Ray French, Cliff Watson, and fellow Welshmen Kel Coslett, John Warlow and John Mantle, and also winning selection for Commonwealth XIII and full caps for Great Britain. Merv Hicks represented the Commonwealth XIII rugby league team while at St. Helens in 1965 against New Zealand at Crystal Palace National Recreation Centre, London on Wednesday 18 August 1965,
The offer to start a new life with the Canterbury Bankstown Berries in the Sydney Rugby League competition led Hicks to Australia with his wife, Gwyneira, and Andrew, in 1966. Two daughters, Julie and Tanya, followed in 1967 and 1970. Five highly successful seasons with the Berries including a grand final in 1967 ended with his move to the NorthSydney Bears as captain-coach for the 1971 and 1972 seasons. Although these were lean times for the Bears and an injury stricken Hicks, they managed to beat all of the finalists of those years when Hicks was on the field, as well as creating many headlines with the hard-hitting antics of the captain and his fellow Welsh import, 'Big' Jim Mills. His 7 seasons in the Sydney competition were highlighted by an ultimately unsuccessful newspaper campaign to have the international representation rules changed so that he could be picked for New South Wales and Australia, such was his dominance at club level. A short season with the Orange CYMS in country NSW had sufficient impact on the district that he was named in the club's "Team of the Century". The Hicks family then returned to the north of England.
Later career
Hicks returned to the north of England for four seasons to finish off his first class career with Hull FC, Leeds and Bradford Northern. Having played in an era when Wales was not represented on the international stage during his first stint in British rugby league, his selection for Wales for the 1975 Rugby League World Cup was denied by a broken arm. Nineteen seasons of professional rugby league ended for Hicks with three years at the Bowral Blues in Group 6 of the New South Wales country rugby league.
Coaching career
After retiring from playing, he coached several teams including Bowral, Group 6, Southern Division, Junee and Riverina in the country championships. Hicks now lives with his wife Gwyneira, on the Central Coast of New South Wales and works in the hotel industry.