Born in Enfield, London, Slabber joined Tottenham Hotspur as a trainee in August 2001, where he was mainly used as a reserve team player. He made just one appearance in the Premier League, coming on as a substitute in the 79th minute for Gary Doherty against Liverpool in a 3–2 defeat on 16 March 2003. He set up Teddy Sheringham for Tottenham's second goal, four minutes from the end. He had loan spells at Danish outfit AB Copenhagen in 2004, and Swindon Town in 2005.