Chelsea will appeal to the Court of Arbitration for Sport in Lausanne against a FIFA ban on transfers into the club this summer.
The club, who finished third in the English Premier League but were 26 points behind champions Manchester City, have already accepted they will lose Eden Hazard to Real Madrid in the summer.
Hazard, 28, has a year left on his contract and has refused to sign an extension despite persistent overtures from manager Maurizio Sarri and owner Roman Abramovich.
He joined from Lille for £32 million seven years ago and has almost single handedly dragged a fairly mediocre Chelsea squad into the Champions' League qualification places.
Hazard blew a kiss to Chelsea fans after the 0-0 draw with Leicester on Sunday, 12 May, and said he had privately informed the club of his decision.
"I have made my decision, that's it," he said after the game.
"When you are on the pitch, you try to be focused on the pitch with the ball. That's it. When I am on the pitch I just try to do the best. I am not thinking about this and this, my situation or the club's situation. I just try to win games," the Belgian told reporters.
Hazard will lead Chelsea into the Europa League final against Arsenal in Baku, Azerbaijan on 29 May and it is an open secret that he will join Real Madrid during the transfer window, with the only question being the price tag.
Chelsea are expected to be holding out for £100 million but with Hazard having only one year left of his contract, it may be hard for them to force Real to pay more than half that price.
On Monday, 13 May, there was a report in France's L'Equipe newspaper that a deal had already been agreed.
"I know very well that Eden tried to do his best for seven seasons at Chelsea. He did very well, he has become one of the best two or three players in the world, but I think also that we have to respect him and his decision," Sarri said after the game.
But the big problem for Chelsea is how will they will replace Hazard and beef up their squad in order to challenge Manchester City and Liverpool next season.
In February Chelsea were banned from signing players during the next two transfer windows, meaning they cannot bring in anyone until the summer of 2020.
It followed FIFA's investigation into their signing of young foreign footballers.
"Chelsea categorically refutes the findings of the Fifa Appeal Committee," the club said in a statement.
Fifa said it found breaches in 29 cases
Football fans may wonder why they are expected to feel sympathy for Chelsea when the club currently have 41 players out on loan at other clubs.
These include strikers Tammy Abraham, Michy Batshuayi and Alvaro Morata, who have been banging in goals on loan at Aston Villa, Crystal Palace and Atletico Madrid respectively.
Chelsea also signed 20-year-old American-born midfielder Christian Pulisic from Borussia Dortmund in January for £58 million and promptly loaned him back to the Bundesliga club.
Pulisic scored a spectacular solo goal against Werder Bremen earlier this month and experts say he has the potential to be another Hazard.