AC Milan's Andriy Shevchenko has been in London for talks and a medical ahead of an expected transfer to Chelsea.
Mourinho wants Shevchenko to play in attack with Didier Drogba
Earlier on Wednesday Chelsea confirmed Milan had given them permission to speak to the 29-year-old.
Now it has emerged that Shevchenko has been at Stamford Bridge to discuss his personal terms and also undergo a medical, which he would expect to pass.
It is thought a price for the transfer has been agreed with Milan, with reports suggesting it could be £34m.
That would break the current British transfer record, which stands at £30m, paid by Manchester United to Leeds for Rio Ferdinand in 2002.
Earlier on Wednesday a leaked comment allegedly made by Chelsea striker Didier Drogba made it clear that the Blues were already making plans for the arrival of Shevchenko.
Bernard Lacombe, an adviser to Lyon president Jean-Michel Aulas, spoke to Drogba on Tuesday and said the Ivory Coast forward told him "that Mourinho wanted to build the team around him and Andriy Shevchenko".
Lacombe added: "Didier will not be coming to Lyon."
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Hernan Crespo; Parma - Lazio £35.5m
Gianluigi Buffon; Parma - Juventus £32.6m
Christian Vieri; Lazio - Inter £31m
Shevchenko is expected to undergo a medical later on Wednesday but Chelsea have stressed: "No deal has been done yet."
The Ukraine striker had earlier told Milan vice-president Adriano Galliani: "I'm leaving for family reasons."
Shevchenko has an American wife and it is understood that they want their son Jordan to learn English.
The striker added: "It wasn't a problem of relations and there is no economic problem."
Galliani said: "This is certainly the most painful divorce since I have been at Milan. We will begin negotiations with Chelsea and it will not be easy."
Galliani, who is in charge of the day-to-day operations at Milan, added: "It's a victory of the English language over the Italian language.
"I've tried to convince him to stay - even one minute prior to the press conference."
Milan offered Shevchenko a contract extension until 2011.
"My wish is that the club can evaluate my transfer," added the Ukraine international.
"Of course I am saddened because I have seen the looks on the faces of the fans and because of the many messages I have received."
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Wayne Rooney: Everton - Man Utd £27m
Michael Essien: Lyon - Chelsea £24.5m
Didier Drogba: Marseille - Chelsea £24m
Shevchenko's wife, Kristen Pazik, is understood to be friends with the partner of Chelsea owner Roman Abramovich.
"My wife has nothing to do with this," said the striker. "We decided together for the best interests of our family.
"I don't speak English, my wife does not speak Ukrainian - the only language we have in common at the moment is Italian.
"The only way to be able to teach our children our love that we have for them is the English language."
Shevchenko joined Milan from Dynamo Kiev in 1999 and is the second highest scorer in the club's behind Gunnar Nordahl with 173 goals.
He scored 19 goals in 28 Serie A matches this season and also netted nine goals in the Champions League.
Shevchenko will captain Ukraine at the World Cup finals in Germany this summer.