Danny Mills has tipped West Ham to sell a first-team star like Issa Diop after paying big-money to sign Pablo Fornals from Villarreal last week.

Speaking exclusively to Football Insider, the ex-England international claims the capture of the Spanish attacking midfielder is likely to create a transfer domino effect that could mean a big name being sold this summer.

West Ham announced the signing of Fornals, 23, last week after agreeing a £24million fee and a five-year contract with the player that means a deal worth what Football Insider understands is a total of £40million.

Manchester United have been strongly linked with a swoop for centre-back Diop over the last week, and, although the Hammers’ stance is that the player is not for sale, Mills believes it will be a different matter behind the scenes.

“West Ham have been looking to add quality to their squad and it’s clear Manuel Pellegrini wants his team to be attacking and move the ball around quickly with technical players, like he had at Man City,” Mills told Football Insider.

“Lanzini has been okay, but he has had some bad injuries and West Ham have never really replaced the creativity of Dimitri Payet. Fornals has been brought in by Pellegrini to add invention.

“The problem at a club like West Ham is that this creates a domino effect. You add a quality player in and a quality player from the first team goes out of the door. For a club, who don’t have an abundance of riches, that’s often the way.

“Man United have been linked with Issa Diop. West Ham want a lot of money for him, but I wouldn’t be surprised if they sell him at all.”

Diop joined West Ham last summer for £22million from Toulouse and had an impressive debut campaign, forming a sound partnership with, first, Fabian Balbuena and, then, Angelo Ogbonna.

The Frenchman was praised by ex-United manager Jose Mourinho following the Hammers’ 3-1 win against United in October, as he lauded the London club’s scouting team for recommending him.

In other West Ham news, it can be REVEALED that the club have agreed the terms of a stunning mega-money deal.