Chelsea manager Jose Mourinho has explained his thinking behind the decision to chase Everton defender John Stones.
The Blues saw a £20m bid rejected by the Toffees earlier this week, but the Premier League champions are expected to return for the youngster.
Mourinho told the club's official TV station: "One more defender and Chelsea will be ready for anything next season.
"I am looking for a defender to finish the balance in our squad and after that we are ready to answer to anything that can happen with our players.
"We would like to have two less than 25 years old, which would give us [strength in that position for] the next 10 years."
Stones moved to Everton from Barnsley in January 2013.
