David De Gea
De Gea is currently in excellent form at Manchester UnitedReuters

Manchester United shotstopper David De Gea's future has again been the subject of speculation after his agent Jorge Mendes hinted that the Spaniard could make a move out of Old Trafford.

The 24-year-old, who joined United from Atletico Madrid for a transfer fee of £17.8 million in the summer of 2011, has been strongly linked with a move to Spanish giants Real Madrid this season.

Although the Spaniard has time and again rubbished the links, insisting that he is happy at Manchester United, he is believed to be still keeping his options open.

Due to this reason, the 24-year-old, whose current contract with Manchester United expires in 2016, has still not signed a new deal at Old Trafford despite there being reports of the Red Devils offering him a new five-year deal worth a whopping £200,000-a-week.

And now Mendes has added more fuel to the fire by refusing to rule out his client's move away from Old Trafford.

"David is amazing, he's brilliant," said Mendes, according to Goal. "He's a Man United player and has a contract there. You have to respect that but things change every five minutes."

Meanwhile, Manchester United boss Louis van Gaal admits that he is not comfortable playing the 4-4-2 system despite the Red Devils finding a lot of success with that formation this season.

Although the Dutchman started with his usual 3-5-2 formation against Queens Park Rangers on Saturday, United were only able to score and win the game after van Gaal changed to 4-4-2 in the second half.

Yet, the former Barcelona boss says that he does not like the 4-4-2 system.

"We have won more with 4-4-2 in a diamond, but when you analyse the game then we have twitched our backsides on the bench," said the United manager, according to Fox Sports Asia.

"I have twitched my backside because we were out of balance. I told my players I was squeezing my backside but [they said] it was the wrong expression.

"All the matches when we play 4-4-2 like against West Ham United [when 10-man United just won 2-1] it was always twitching your backside and I don't like it."