Alex Ferguson's troubles in the transfer market this summer could be exacerbated today with Marcos Senna threatening to pull out of his proposed move to Old Trafford.

The Valencia player's agent, Eli Coimbra, mindful that Ferguson has launched a separate attempt to lure Owen Hargreaves from Bayern Munich, has claimed the deal will be off unless it is completed before an 11.0am deadline.

"For 20 days we have been negotiating with Manchester United over the transfer of Marcos," he said.

"In that time, they have twice requested a deferral before finalising the negotiations. This situation has gone on a long time already and we cannot wait any longer.

"We understand Manchester's situation, but we also know that Villarreal are unhappy because they want the situation resolved. For that reason, if by noon on Friday [ Spanish time] there is no definitive agreement, the player's decision will be clear: he will stay with Villarreal."

United's interest in Hargreaves has prompted the player's agent, Roman Grill, to claim the midfielder has requested a meeting with Bayern's coach Felix Magath.

Bayern have insisted the 25-year-old will not be allowed to leave after recently signing a contract extension until 2010, but Grill said: "It's not a question of whether the club want to discuss a transfer.

"It is obvious that they need players like Owen and they don't want him to leave, but on the other hand, the player wants to talk."

United are still smarting after learning on Wednesday that Wayne Rooney and Paul Scholes will have to serve three-match suspensions.

Gary Neville, the captain and a man who has never been afraid to speak his mind, revealed the club's anger with the Football Association last night by branding their decision to ban Rooney as "absolutely shocking".

Neville expressed further outrage that the FA had also suspended Scholes after he and Rooney were sent off against Porto in a pre-season tournament in Amsterdam this month.

Both players will be available for United's opening Premiership match of the season at home to Fulham on Sunday, but will not be eligible again until September 17th, missing trips to Charlton and Watford and a home game against Tottenham.

"I think the decisions to ban them are shocking, absolutely shocking," said Neville, who was fined by the FA after his provocative goal celebrations in front of Liverpool's supporters in January.

"But to be honest with you, what do you expect? I didn't expect anything else. What frustrates me is that in this country we don't look after our own."

United's hierarchy have not made any official comment, taking a diplomatic stance that may have something to do with the fact that the club's chief executive, David Gill, has recently been appointed to the FA's board.

Ferguson is known to be furious, particularly in the case of Rooney, whom he believes has been punished because of "his name".

Ferguson, expected to air his grievances at a press conference today, is convinced United are unfairly treated compared to other clubs. He has cited the fact that two Liverpool players, Steven Gerrard and Neil Mellor, were sent off playing against Galatasaray in the same tournament three years ago, yet did not receive any further punishments from the FA.

On that occasion, the organisers of the four-team competition agreed beforehand that any disciplinary issues would not carry over into domestic competition and the Dutch football authorities chose not to forward the matter to their English counterparts, an explanation that has done little to appease Ferguson or Neville on the back of a turbulent summer for United.