Chelsea have consulted lawyers after allegations of a bust-up involving manager Jose Mourinho and chief executive Peter Kenyon over the sale of William Gallas to Arsenal.
Reports have suggested the pair fell out over the decision to off-load the unhappy France international defender as part of the deal to bring England left-back Ashley Cole to Stamford Bridge.
The transfer was concluded just minutes before the midnight deadline on transfer-deadline day, with Chelsea paying Arsenal £5million plus Gallas in exchange for Cole.
The Blues maintain Mourinho's relationship with Kenyon is strong and the pair were in constant contact throughout yesterday as efforts to bring Cole to Chelsea gathered pace.
Gallas, who irked the Chelsea coach by failing to join up with the squad on their pre-season tour of America, had been omitted from the first team this season.
Mourinho, with Kenyon's agreement, was prepared to let the defender play solely reserve team football for the final year of his contract if they could not engineer a sale which suited the Blues - however disruptive that might have been for the squad.
Chelsea were not prepared to sell Gallas outright to Arsenal, or any other club for that matter, as the club would have been perceive that outcome to be a victory for the 29-year-old.
Clearly the best solution for the Blues was to be rid of the player, in a deal they were happy with and their player-plus cash agreement with Arsenal for Cole brought about an ideal conclusion to one of the longest running transfer sagas of the summer.
But the Chelsea coach has since been left fuming by suggestions that Kenyon went behind his back to dispose of Gallas and - as a result - it is understood that the club have held lengthy discussions with their lawyers over possible legal action.
Cole returned to training with England today ahead of their Euro 2008 qualifier with Andorra tomorrow and is delighted to have finally made the switch across the capital.
But while Cole celebrated his move, the club's midfielder Claude Makelele confessed he had been forced to join up with France.
The 33-year-old retired from international football after the World Cup final and underlined his decision with a letter to the French Federation on August 22.
But France coach Raymond Domenech selected Makelele for France's Euro 2008 qualifiers and threatened him with domestic suspension under FIFA's rules.
Mourinho hit back by accusing France of treating Makelele like a 'slave' and Chelsea confirmed the player had sent a retirement note to the French FA two days prior to his controversial call-up.
Now Makelele still insists he wants to quit the international scene and hinted that the next two qualifiers will be his last for the country.
Makelele said: 'I said after the World Cup that I would take international retirement, on television and with a note sent to the federation.
'I truly wanted to retire. The fact that he has put me in the squad has turned things upside down. From a legal point of view, I had to be here. Chelsea authorised me to play so that they do not incur any sanctions.
'The coach wanted me to make a comeback when I had told him I didn't wish to return.
'I will be there to win these two very important matches and I hope that afterwards the situation will be resolved so that there is no ambiguity.
'It is necessary now to let the squad get on with work and that the soap opera ends this week.'