Sir Alex Ferguson believes Gabriel Heinze owes to the club to stay at Manchester United.
Heinze is currently at the centre of a transfer tug-of-war between United and Premier League rivals Liverpool.
Liverpool are keen to sign the Argentine defender and have tabled a bid for the former Paris Saint Germain star.
United are adamant they will not sell Heinze to their bitter rivals even though Heinze's agent reputedly has a letter which gives the defender permission to leave Old Trafford for the fee that Liverpool have offered for the South American.
Liverpool have instructed their lawyers to pursue the move for Heinze, but Ferguson remains determined to stop the player making the switch to Anfield.
The Scot feels Heinze should show loyalty to United because of the way the club helped him recover from his serious knee injury two years ago.
"He is still our player and that is the most important thing," Ferguson told Sky Sports News.
"He still has two-years left on his contract and I think we have stood by Gaby very well.
"He had his cruciate knee operation, we looked after him and we let him him do his rehabilitation in Spain which he wanted to do.
"We conducted ourselves in a way that suited Gaby perfectly and he was delighted the way we looked after him.
"I think if we take away the agent's role in this I don't think there is an awful lot wrong with Gaby's position at the club."
Ferguson also believes Heinze may have helped United's cause in their bid to sign Carlos Tevez by recommending the Premier League champions to the West Ham forward.
United remain hopeful of signing Tevez despite the move being held up because of a wrangle over his ownership rights between West Ham and the player's representatives.
Tevez is determined to join United and Ferguson believes Heinze may have persuaded his fellow Argentine to make the move to Old Trafford.
"I think the fact they have been in the Argentine team the last few weeks I am sure Gaby has told him how good a club Manchester United is, because there is no other thing you can say about Manchester United from his own experiences," added Ferguson.
"Maybe that in some way has helped Carlos Tevez to know he is coming to the right club."