Kalidou Koulibaly to Chelsea: £70-80m transfer would be 'dead money', says Rio Ferdinand

Rio Ferdinand believes Chelsea would be taking a risk in they were to sign Kalidou Koulibaly due to the Napoli defender's age.

The Senegalese international is seen as one of the best centre-backs in the world and has been linked with a move away from Naples for many years but has so far stayed put.

Frank Lampard is known to want to improve his defence this summer, and the Blues' frailties were on show again on Saturday night as their season came to an end with a 4-1 thumping at the hands of Bayern Munich.

However, speaking on BT Sport's coverage of that game, Manchester United legend Ferdinand warned that making would be an extremely expensive move for Koulibaly might not be wise.

"The problem with Koulibaly is that he’s 29 years old," he told BT Sport. "It’s dead money. You spend £70-80m to get him and that’s dead money, from a business perspective.

"Is that the right way that Chelsea want to go? Who knows."

Lampard has already made significant moves to bolster his attacking options ahead of the new campaign, with RB Leipzig striker Timo Werner and Ajax winger Hakim Ziyech joining the club.