Sir Alex Ferguson claims Darron Gibson has been left in limbo after Sunderland reneged on a deal to sign him.
Sunderland made a triple offer to Manchester United for Gibson, Wes Brown and John O'Shea during this summer's transfer window.
Brown and O'Shea completed their moves to the Stadium of Light, but Gibson's switch to Wearside has fallen through.
Ferguson believes the reason for the move not happening is down to Sunderland moving the 'goalposts' as they changed their offer for the Republic of Ireland international.
"He was at the point of going to Sunderland and somewhere along the line, I don't know exactly when, I think Sunderland moved the goalposts," said Ferguson.
"I suppose their job is to try and save money.
"From what I can gather, they gave him an offer and then changed it. That annoyed Darren and I think he's quite right.
"If you can't trust them on day one why wait until day two?"
Ferguson admits Gibson, who has been left behind from United's tour of the USA as he looks to sort out his future, has been left in limbo by the collapse of the Sunderland move.
"Darron was undecided about what to do when we made the group up to come here - and we both felt he'd be better staying back," added Ferguson.
"He seems to be in limbo at the moment."