Andriy Shevchenko was the cause of Chelsea owner Roman Abramovich's original rift with Jose Mourinho, it has been revealed.

A key member of staff at Chelsea during Mourinho's last reign cites the signing of Shevchenko as the principal source of tension between owner and manager.

"Roman's principal interest is the players and their recruitment," he told the Mail on Sunday. "And Roman does have a lot of advisors around him who all offer an opinion. But Roman is a sponge for information and he has absorbed a lot in 10 years. I would imagine it will now be a more studied view between them on who to target."