Chelsea owner Roman Abramovich isn't ready to sign off on the deal for Atletico Madrid striker Sergio Aguero.

The Daily Star says the Russian is reluctant to splash out a British record fee despite Aguero scoring twice against the Blues in their Champions League clash - as he is not sure if the striker is worth £40m.

With annual wages of £6m, a five-year deal would cost the tycoon a staggering £70m.

And Abramovich has yet to be convinced that would be value for money.

Despite his massive wealth, Abramovich has baulked in more recent times at spending vast amounts of money on players, aiming to try to see the club break even over one year.

A source close to Abramovich said: "Roman hasn't decided yet on Aguero.

"It is an awful lot of money to pay and he is not going to rush into it."