Vassell began his career at his home town club Aston Villa in the Premier League, being developed by their academy and making his first team debut in 1998.

In October 2010 he was brought back to England by his former international manager Sven-Göran Eriksson to play for the Championship side Leicester City.

Under Eriksson with England, Vassell scored six goals from 22 international caps awarded between 2002 and 2004, including appearances at the 2002 FIFA World Cup in South Korea and Japan, and UEFA Euro 2004 in Portugal.

He first played football with local junior team Romulus in the Birmingham Boys League scoring a record of 46 in a season and 6 in 1 match.

[7] This run ended on 22 April 2011 when he scored for Leicester City during the 3–2 defeat to Nottingham Forest.

[8] During his first season for Manchester City, Vassell scored eight league goals in 35 appearances, forming an effective partnership with Andy Cole.

In the latter half of the season, many of his appearances were as a wide midfielder, as manager Sven-Göran Eriksson adopted a defensive 4–5–1 formation.

Vassell scored his 50th Premier League goal on 10 February 2008, in the victory against local rivals Manchester United.

On 29 October 2011, he suffered a serious knee injury in a game against West Ham United which ruled him out for the rest of the season.

[17] Vassell made his England debut on 13 February 2002, in a man of the match performance against Netherlands in a 1–1 draw.