El Mundo Deportivo, which has close ties to Barca, says the Blues had reached an agreement with Fabregas.
However, the clubs still need to agree a fee for the Spain star. It is believed Barcelona are holding out for £29.2m.
Fabregas' agent Darren Dein has been instrumental in bringing his client back to the Premier League.
Fabregas reportedly would have preferred a move back to Arsenal but when it became clear that was not a possibility, he was eager to stay in London.
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