Chelsea have slammed Fifa for “choosing to treat Manchester City entirely differently” after their transfer ban was lifted.

After the Court of Arbitration for Sport reduced their two-window punishment for breaching rules on signing underage players, the Blues were given the green light to enter the January market.

However the club released a statement on Friday questioning how they were dealt with compared to Premier League rivals City.

It read: “Chelsea is grateful to the CAS for the diligent approach that it gave this matter. The club has not yet received the written reasons for CAS’s decision but wishes to make the following clear:

“The approach taken by Fifa to this case has been deeply unsatisfactory, not least as Fifa chose to treat Chelsea entirely differently to Manchester City for reasons that make absolutely no sense to Chelsea.”

Their fury centred around City stretching out their own underage signing breaches so that they were judged under the 2019 version of Fifa regulations, allowing the Prem champs to plea bargain with Zurich bosses, whereas Chelsea case was dealt with under the previous rules in place, report The Sun.

Chelsea were furious at being initially found guilty of more than 150 breaches, arguing the vast majority were little more than administrative oversights not helped by a lack of clarity in both Fifa and FA regulations.

Blues lawyers are understood to have contended the punishment was disproportionate to the offences, while similar breaches at other clubs – including City – have gone unpunished.

The Blues also attacked a charge relating to 16 players – who they state were registered to the satisfaction of the Premier League and FA – as “perverse”.

In outling how the 27 youngsters involved in the case were signed, they say: “Of those, 16 players were registered by Chelsea in exactly the same way as other Premier League clubs registered players at the time.

“Furthermore, Chelsea sought clarification from the Premier League in 2009 about whether it needed to apply for permission to register players in this category.

“The FA subsequently liaised with Fifa and it was confirmed to Chelsea that players in this category were entitled to register and that no special application was required (and in fact no special application process existed).

“Accordingly, the fact that Fifa brought charges against Chelsea for this category of player was perverse. We are grateful that this appears to have been corrected by the CAS.”