West Ham boss Slaven Bilic turned down the chance to sign Renato Sanches on loan, according to David Sullivan

West Ham boss Slaven Bilic rejected the chance to sign both Renato Sanches and Grzegorz Krychowiak this summer, according to Hammers joint-chairman David Sullivan.

In one of the shock moves of the summer transfer window, Euro 2016 winner Sanches joined Swansea on a one-year deal after being allowed to leave Bayern Munich on loan - less than 18 months after joining the Bavarians in a £27.5m transfer from Benfica.

Sanches is set to be reunited with Swans boss Paul Clement, who worked alongside the Portuguese youngster during his time as assistant coach to Carlo Ancelotti at the Allianz Arena.

Sanches eventually joined Swansea on loan in one of the shock moves of the summer

However, Sullivan claims Sanches could well have signed for West Ham this season if Bilic had given the transfer his approval.

"Grzegorz Krychowiak and Renato Sanches were both offered to the manager before their switches elsewhere, but he told us that he is happy with the squad he has," Sullivan said.

"As a Board we are behind Slaven, and he believes he has the tools to turn around our form and rectify our disappointing start to the season."

Sullivan claims West Ham could also have signed Grzegorz Krychowiak this summer

West Ham signed a number of fresh faces over the course of the summer window, with Pablo Zabaleta, Marko Arnautovic and Javier Hernandez among the new arrivals.

However, the London Stadium club missed out on William Carvalho after Sporting Libson left it too later to accept a bid from the Hammers.

"Overall Slaven is happy with the business we have done during the summer transfer window," said Sullivan. "We received the manager's wish-list before the window opened and we have managed to get the top four players on it.

Bilic is happy with his squad at the London Stadium, according to the West Ham joint-chairman

"It is no secret that we made a club record bid for Sporting Lisbon's William Carvalho but unfortunately that offer was rejected a couple of weeks ago.

"Late last night Sporting Lisbon made contact to accept the original offer, but unfortunately it was just too late in the day, and we simply did not have enough time to put the player through a medical.

"We were not prepared, as a club, to buy a player for that amount of money without him having gone through adequate medical checks."