Denis was a prolific striker who scored many goals for Clifton All Whites. Once for the Under 15s in the Intermediate league in the Young Elizabethan league he scored 6 goals against Bunny FC in the 1974/75 season.
He was a popular player, with tenacity for scoring goals and a broad smile. During his time he was also a coach for the Under 11 Clifton All Whites and Nottingham Forest Academy, which is where his son, QPR and England star, Jermaine Jenas, began his career
Dennis played for Burton Albion, Grantham, Buxton, Matlock Town, Shepshed Charterhouse, Kettering Town, Wellingborough Town and Eastwood Town, before he returned to Grantham in November 1985 to make a lone appearance in the game against Rushden Town.
His playing career continued at Arnold Town and Alorton Town, where he finished for both clubs as the season’s top scorer, winning two league championship medals.
A brief period was then spent with Kelsi in Finland’s Division Three, as their player-coach, after he had become only the third coloured player to achieve the FA’s full coaching licence.

Dennis moved to the United States, where he worked as a Football Coach for Albuquerque Asylum Football Club, New Mexico.