Monday, August 6 promises to be D-day in the Manchester United career of Gabriel Heinze.

The Argentina defender has taken the extraordinary step of seeking legal advice to see whether he has grounds for pursuing a complaint against his club over their refusal to sell him to Liverpool.

Heinze’s action is staggering and will almost certainly signal the death knell on his time at Old Trafford.

Yet Sir Alex Ferguson has made it perfectly clear not only does he believe United have right on their side, he expects Heinze to honour his contract and turn up for training as planned.

“He is due back in training on August 6, which gives him three clear weeks’ rest after the Copa America. And we expect him back,” said the United boss.

The deadline effectively gives Heinze’s lawyers a week to find out if the former Paris St Germain defender has a case, which revolves around whether a letter, signed by chief executive David Gill, confirming the figure United would be prepared to sell Heinze for, overrides the player’s contract, which still has two years to run.

Gill claims he informed Heinze’s agent verbally, prior to Liverpool revealing their interest, that United would not be prepared to sell him to any of their three major domestic rivals – a discussion which is thought was recorded and could, therefore, in theory, be used as part of any defence the Red Devils may wish to put forward in court.

Heinze has been the subject of interest from overseas, with Real Madrid and Inter Milan among the clubs to express an interest.

But the huge Spanish-speaking influence at Liverpool, plus an opportunity to remain in the north-west, appears to have an irresistible lure for the player.

And, after pinning much of the blame for the present situation on Heinze’s agents, Ferguson must now accept the defender is also a prime mover.

“We are aware Gaby is taking legal advice,” confirmed the United boss.

“That is good. I hope it is good advice because we are confident of our position.”

At least Ferguson had other, more positive thoughts to occupy his mind as United headed back to England after a successful two-week trip to the Far East.

His £17million summer purchase from Sporting Lisbon, Nani, must be a source of considerable satisfaction.

The brilliant chip he produced in the 3-0 win over Shangzhou Pharmaceuticals was one of the highlights of the entire trip.

Having heeded Ferguson’s advice to cut out the elaborate back-flip goal celebrations, Nani is clearly a quick learner.

And provided he soaks up a few lessons over the next fortnight, the 19-year-old could be an influential figure in United’s pursuit of glory this term.

“We are trying to give him the football, mixed with a training programme that gets him up to our level,” said Ferguson.

“He is nowhere near that at the moment. But there are good signs. Some of his skill and speed at times is quite impressive.

“Scoring two goals in two games is a good start but I do think you will see a different player in two weeks’ time.”

Wayne Rooney and Lee Martin were also on target but there was no goal on home soil for Dong Fangzhou, while Alan Smith did not make much impression either.

With United remaining confident Carlos Tevez will arrive before the August 31 transfer deadline, it is difficult to see Smith hanging around much longer as he falls further down the pecking order, and it appears just a question of time before he moves on.