West Ham are standing behind chief executive Scott Duxbury despite reports his position is under threat because he was their legal adviser at the time of the Carlos Tevez saga which may see them lose up to £30m after an independent tribunal ruled in favour of Sheffield United.
The club said in a statement on their website: "We acknowledge again that the club broke Premier League rules in the original signing of Carlos Tevez but we were dealt with accordingly by an independent Premier League commission and accepted the significant punishment handed down at that time.
"In light of this and the wider implications of this latest ruling for English football we have decided to ask that the case be considered by the Court of Arbitration for Sport."
The tribunal's findings stated that Tevez's services were worth at least three points to West Ham over the season and made the difference between the Hammers remaining in the Premier League and being relegated at the end of the 2006/7 season.
They also said that if talks between Tevez's agent Kia Joorabchian and West Ham had been known to the Premier League they would have prevented him playing the final few games of the season.
The findings state: "If the Premier League had known what Mr Duxbury for West Ham was saying to Mr Joorabchian's solicitor [Graham Shear] following the commission decision, we are confident the Premier League would have suspended Mr Tevez's registration as a West Ham player."
Duxbury and then-Hammers chairman Eggert Magnusson insist they have never denied meeting Tevez's representatives at that time but that they were only to seek to either keep the player at Upton Park or find a way to sell him that would be approved by the Premier League.
A club spokesman added: "The position of Scott Duxbury is not under review."