Non-league and a move to Watford

Agana started his football career with non-league side Welling United whilst working full-time for an insurance company.^[3] When his employers moved their offices to Poole he became a part-time professional with Weymouth, signing for £4,500 in March 1984.^[4] He went on to make over 100 appearances for the south coast club and represented the England national game XI during his time there.^[4]

In August 1987 Agana moved into professional football with First Division club Watford,^[4] making his league début at the relatively late age of 23.^[3] Agana made 15 appearances the Hertfordshire side, scoring one goal, as he acclimatised to league football.

Sheffield United

After only six months at Vicarage Road Agana was on the move again, this time to South Yorkshire side Sheffield United.^[3] Dave Bassett, the manager who had signed Agana for Watford, had been sacked in January 1988 and subsequently joined Sheffield United and within days sold Martin Kuhl to his former employers for £40,000, with Agana and Peter Hetherston moving to Bramall Lane as part of the deal.^[3][4][5]

He made his debut for United on 20 February 1988, scoring in a 1–0 home win against Barnsley. Despite this promising start the team was in decline and the club was relegated at the end of the season.^[3] The following season proved a different matter as Agana struck up a striking partnership with new signing Brian Deane. During the 1989–90 season he scored 24 goals in 46 appearances, which, along with a similar tally from strike partner Deane, helped United win promotion from the Second Division at the first time of asking,^[3] with Agana being named fans' player of the year. The following season saw more of the same, with United promoted again to take them into Division One. That was thanks in part once more to Agana's goals, which included a brace in the 5–2 victory at Leicester City that clinched promotion.^[3]

With The Blades playing top-flight football, Agana's role began to diminish as injuries and a loss of pace began to take their toll^[3] and he was eventually made available for transfer. In three years with the club he scored 52 goals in 154 matches.^[3]

Notts County and back to non-league

In November 1991 Agana signed for Notts County for a fee of £685,000 – which was a club record transfer fee at the time.^[3] He was loaned to Leeds United briefly in February 1992 and contributed to their 1992 First Division title with two league appearances.^[6] He went on to play 145 times for Notts County, scoring 15 goals.

After leaving County he went on to play for Hereford United, Cliftonville, Leek Town^[7][8] (including a six-game spell as caretaker manager in 1999^[9]) and Guiseley,^[10][11] where he was player-manager.^[12]