The area was in the midst of an economic downturn following the end of the Second World War and a falling demand for coal, one of the main industries of the region, which also affected the local docks.

Dwyer grew up supporting Cardiff City and began attending matches at the club's home ground, Ninian Park, from a young age.

Often unable to afford the entry fee for matches, he and his friends would often sneak into the ground by climbing disused railway sleepers to scale the fencing around the stands.

[11] Dwyer attended Bishop Mostyn High School in Ely as a teenager,[8] but later admitted to having little interest in pursuing his academic studies, choosing to focus on his sporting activities.

[13] Dwyer's childhood dream was to become a professional footballer and his career began to progress at the age of 14 when he was picked to represent the Cardiff Schools side for the first time.

He gained international recognition soon after when he was selected to represent Wales at under-15 level in the Victory Shield, a youth competition held between the Home Nations.

Despite the team's disappointing league form, Dwyer ended the season by winning his first senior trophy as Cardiff defeated Bangor City 5–0 in the final of the Welsh Cup.

[25][27] The previous season's low finish prompted Scoular to release several of Dwyer's youth teammates who had been promoted to the senior squad.

Cardiff's results gradually stabilised under O'Farrell, with Dwyer scoring his first senior goal for the club in a 2–0 victory over Preston North End on 9 March 1974 after heading in a cross from Leighton Phillips.

Dwyer won his second Welsh Cup at the end of the season, as Cardiff defeated Stourbridge under Jimmy Andrews, who had previously been O'Farrell's assistant.

With Cardiff trailing 5–1, a frustrated Dwyer deliberately collided with Millwall goalkeeper Ray Goddard causing the opposition player to be stretchered off the field with a concussion.

This proved fruitful immediately as he scored a brace in his first match in the new role and was denied a first career hat-trick when he missed a penalty late in the game.

He had continued to play baseball alongside his football career, concealing the fact from the staff at Cardiff, and hid the cause of the injury by claiming he had fallen down the stairs at his home.

[43] Ahead of the 1977–78 season, Cardiff were struggling financially and the club was dealt a further blow by the restriction of crowd numbers at Ninian Park due to safety concerns.

Dwyer was offered wages considerably higher than those he received with Cardiff, a villa and places at an English school for his children but the move broke down when Andrews refused to contemplate selling.

An injury crisis amongst Cardiff's attacking players also led Andrews to use Dwyer and fellow defender Paul Went in forward roles in an attempt to utilise the pair's physical presence.

[50] Despite his inexperience, Morgan led the club to their highest finish in nearly a decade, with Dwyer remaining a lynchpin of the side making 45 appearances in all competitions, having reverted to his traditional defensive role.

[55] The start of the 1980–81 season coincided with Dwyer's twentieth year with Cardiff and chairman Bob Grogan arranged a testimonial match against Stoke City.

[58] Morgan made several signings, including brothers Gary and Dave Bennett and steered the club to ninth place before he was relieved of his role and moved into an administrative position.

[59] The club endured a disastrous run of form under Morgan's replacement, Graham Williams, failing to win a game for more than three months between December 1981 and March 1982.

[60] Dwyer played his last game of the season on 27 February in a 2–0 defeat to Sheffield Wednesday before succumbing to a knee injury, caused by arthritis brought on by an operation on his cartilage earlier in his career,[61] that ended his campaign.

Relegation had prompted rumours of a clearout of players at the club and, while recuperating in hospital, Dwyer read in the South Wales Echo that he was due to be released.

[68] Dwyer remained a mainstay of the side for the rest of the campaign as the club embarked on a strong run of form that ultimately ended in winning promotion back to the Second Division after finishing second.

The season was marred by an FA Cup upset defeat to non-league side Weymouth in which Dwyer was at fault for the winning goal after losing possession on the edge of his own penalty area.

Although Dwyer had a brief highlight, scoring the winning goal against his boyhood idols Leeds United in mid-September, the club recorded five straight defeats in their following fixtures.

On 17 February 1985, Cardiff suffered a 4–1 home defeat to Notts County and a furious Dwyer returned to the dressing room after the match and lambasted several of his teammates after believing that they had given up during the game.

[87][88] A goalless draw with England left Wales and Northern Ireland in a deciding fixture in the final match to determine the tournament's winner.

The match eventually ended in a draw which resulted in Northern Ireland winning the title as Wales finished as runners-up for the second consecutive season.

[56] Harry Parsons, who initially brought him to Cardiff City, remarked that Dwyer "was solid and hard when I first saw him play, although he didn't look much like a footballer with his shovel feet.

"[91] Roger Gibbins, who won promotion with Dwyer in 1983, described him as "an out-and-out centre half who was good in the air, competed very well and who put his head in where it hurt.