The Red Devils have endured a difficult run in all competitions after exiting the Europa League following a 3-1 aggregate defeat by Liverpool.
The 20-time English champions lost 1-0 to West Bromwich Albion last time out in the Premier League, whilst United drew 1-1 with West Ham United in their FA Cup quarter-final.
Van Gaal hasn’t won any silverware since the former Barcelona and Bayern Munich manager took over the reins from David Moyes in 2014.
Retired Republic of Ireland and Leeds midfielder Giles reckons there are very few signs of real progress at Old Trafford under the Dutch coach.
“He changes it so much it is difficult to know what the best team is for Man Utd,” Giles said.
“When you look at Louis van Gaal, he has been there 18 months and we should be seeing some real proof of what he is trying to do.
“Every time I watch Man Utd, it’s like they’re starting again.”
United are in action against Manchester City in Sunday’s derby at the Etihad Stadium.
The Red Devils will face the Hammers in the FA Cup quarter-final replay at Upton Park next month.
MORE: Man United latest news
MORE: Arsenal latest news
MORE: Chelsea latest news
MORE: Liverpool latest news