Chelsea and Valencia have reached "an agreement in principle" for the transfer of winger Juan Mata to the Blues.

The 23-year-old Mata is on his way to London to undergo a medical and agree to personal terms ahead of the move, which is reportedly worth around $38 million.

Mata joined Valencia in 2007 from Real Madrid and emerged as a key component for Los Che during his four seasons at the Mestalla, making over 120 appearances in the league and tallying 32 goals.

In addition to being a member of Spain's 2010 World Cup winning squad, Mata led the Spanish Under-21 team to glory at this summer's European Championship.