The Stamford Bridge club know Courtois, whose deal expires in 2019, is wanted by Real Madrid and Paris Saint-Germain, and face a battle to convince him his future remains in London. They have been aware of Madrid's threat since the end of last season and have started to make contingency plans should Courtois opt to go. Butland is regarded as one of the best goalkeepers in Europe and, at 24, has plenty of time to improve. Though currently out with a broken finger, he is expected to return to first-team action within the next fortnight and tipped to establish himself as England's No 1 ahead of Joe Hart for the World Cup in Russia. Stoke would not be willing sellers and that would likely push their value beyond that of the British record £30million that Everton agreed for Jordan Pickford. Chelsea wanted Butland while he was at Birmingham City in 2013 but he rejected their advances as he wanted to develop playing regular first-team football and joined Stoke instead for £3.5m. The departure of Courtois, though, would change that with Butland now ready to take on the mantle of being their No 1 goalkeeper.