Kerslake won 29 England youth caps, a record at the time. He made his debut for Queens Park Rangers against Newcastle United in April 1985. He went on to play 58 league games for Rangers, scoring 6 goals. He was transferred to Swindon Town in November 1989. Kerslake moved on to Leeds United, for only 3 months in which he made 8 appearances before moving to Tottenham Hotspur. Spurs paid £450,000 for Kerslake, however he only made 34 appearances in 4 years for them. He was sent on loan to Swindon and Charlton Athletic, before being released whereupon he joined Ipswich Town in 1997. Again he only made a handful of appearances for Ipswich, moving on to Wycombe Wanderers and then finishing his career back at Swindon.
Coaching career
He moved later into coaching becoming assistant mangager at Northampton Town to former teammate Colin Calderwood in 2003. The pair reached the playoff semi finals in each of the first two seasons at the club and in their third and final season at the club achieved automatic promotion into league one in the 2005–2006 season finishing with a club record for clean sheets with 25. He then followed Calderwood to Nottingham Forest, again as assistant managerin the summer on 2006 after the Scot was named as Gary Megsons predecessor. The duo again reached the playoffs in their first season in charge but were beaten on aggregate by Yeovil Town in the semi final. Forest achieved automatic promotion to the Football League Championship in the 2007–2008 season with a run of 6 wins from their remaining 7 games and in the process overcome a 9-point gap with 4 games to go on the teams in the automatic places. Kerslake left Nottingham Forest after Calderwoods sacking in December 2008. Kerslake was appointed first team coach at Watford but on 30 June 2011 was announced the new coach of Cardiff City working under Malky Mackay but this time as assistant manager. Following the sacking of Mackay in December 2013, Kerslake and Joe McBride were placed in charge of the first-team. They were in charge until 2 January 2014, when Ole Gunnar Solskjaer was appointed as the new Cardiff City manager. On 6 July 2015Gillingham appointed Kerslake as Justin Edinburgh's new assistant manager. On 15 January 2017 he was hired again by Edinburgh to be the assistant manager at Northampton Town. On 27 September 2019 he was brought in by Michael Appleton to serve as the new Assistant Manager of Lincoln City.