The former United midfielder has questioned how long fans can rely on the defender's "potential."
News, views and rumours relating to Manchester United in the past 24 hours.
Manchester United boss Louis van Gaal is scheduled to meet with Roma's Walter Sabatini.
Reports suggest Phil Jones is in line for a new contract at Manchester United.
Ex-Liverpool defender Steve Nicol believes Marcos Rojo will prove a great fit in Louis van Gaal's Manchester United side and also thinks his £16 million fee is a solid bargain.
The Netherlands ace took to Twitter with the message that he is 'looking forward to Sunday.'
We compile some of the best photos from Manchester United's training session today.
Real Madrid will not pay Di Maria a salary equal to their top stars' wages, which could be good news for Manchester United.
Manchester United's failure this summer can be highlighted from the amount of first-choice targets Louis Van Gaal's side have missed out on.
Manchester United need to move on signing Ron Vlaar if reports of the interest in the Villa skipper are accurate.