Former Arsenal player Martin Keown has criticised Louis van Gaal's man-management skills following the "farcical" saga involving Manchester United goalkeeper David de Gea.

Van Gaal has not selected the shot-stopper for any competitive match this season due to speculation linking him to Real Madrid.

The Spaniard was due to move to the Bernabeu on Monday, but the deal collapsed after the paperwork failed to get submitted before the midnight deadline.

Keown has also questioned Van Gaal's public criticism of goalkeeper Victor Valdes and suggests that perhaps striker Pedro snubbed United for Chelsea because of the Dutchman's treatment of his former Barcelona teammate.

"The biggest issue for Van Gaal is his man management," Keown wrote in his Daily Mail column. "The David de Gea saga was farcical, but if no offers had been made by Real Madrid until deadline day then he should have been playing. Banishing him to the reserves will have done nothing to encourage him to stay.

"You also wonder whether Van Gaal's treatment of De Gea and fellow Spanish keeper Victor Valdes had any influence on why one-time target Pedro ended up at Chelsea.

"We do not see what happens in the dressing room but it is a concern when former players queue up to criticise Van Gaal's ruthless treatment. Once a relationship is broken, there seems to be no going back."

United spent more than £100m on new players in the summer transfer window.