After impressing for Belgium in the 1986 World Cup, scoring 3 goals on the way to a 4th place finish, David Pleat signed the forward in the following October. Moving from Standard Liege to White Hart Lane, Nico made a great start, making his debut in a 1-0 win at Anfield.
The forward used his speed effectively, latching on to through balls, often played by Hoddle, demonstrating this perfectly whilst scoring his first goal for the club against Norwich City in a 2-1 defeat. Nico settled quickly into English football but a change of formation by Pleat left the Belgian playing in a deeper midfield role, limiting his effectiveness. This was highlighted by being dropped for the 1987 FA Cup final, however Nico came back, performing admirably during his second season, keeping up with Clive Allen in goal scoring terms, despite appearing less frequently.
The arrival of Terry Venables to the manager’s post proved costly to Claesen, who was soon dropped and then sold on to Antwerp in 1989.