Robben move costly - Schuster

Madrid are understood to be ready to pay £20million to land the Holland international.

Schuster said: "It could be expensive. It is necessary to go slowly. We need to be prepared to make signings until the final day of the window. I would be much happier if they were here. The signing of Robben is very important for us."

They have also drawn up a salary package, including image rights, which the Dutchman would accept, but Chelsea coach Jose Mourinho insists he wants the winger to remain at Stamford Bridge.

Robben has two years left on his contract and Chelsea will demand at least £25million if he continues to refuse to sign the new five-year deal he has been offered.

Robben wants a six-figure contract at Chelsea but the offer on the table is for £90,000-a-week - considerably less than top earner John Terry's £135,000-a-week deal and the salaries of other leading stars Andriy Shevchenko and Michael Ballack.

Chelsea are set to increase the pressure on him to make his long-term intentions clear before the start of the season but the Blues are willing to play a waiting game with Frank Lampard.

The England midfielder also has two years left on his contract and has refused the club's offer. However, his agent, Steve Kutner, insists the stalemate will not affect his form.

Kutner said: "If it goes all the way to the last day of Frank's current contract, one thing's certain, Frank will not waver in his commitment to Chelsea."

Mourinho wants the England international to pledge his future to the club but the midfielder is still not entirely happy with the terms of the contract offered to him by the club.