RYAN GIGGS says Manchester United are targeting "proven winners" to strengthen the spine of their side as he set the scene for a spell of major spending.

The assistant manager declared manager Louis van Gaal is looking to sign experienced footballers in the centre of defence and midfield, in the attack and in goal.

United have reportedly had a megabucks bid knocked back by Real Madrid for 29-year-old World Cup-winning centre-back Sergio Ramos.

Germany's World Cup-winning midfielder Bastian Schweinsteiger is another reportedly on Van Gaal's shortlist, although Southampton's Morgan Schneiderlin has also been linked with a move to Old Trafford.

United could require a new goalkeeper if David de Gea joins Real Madrid while they are looking to bolster the forward line after one striker, Radamel Falcao, left at the end of his loan spell and another, Robin van Persie, admitted he is unsure where his future lies.

And Giggs envisages a big summer for United in the transfer market as Van Gaal tries to add players with pedigree in key positions.

"If there are players available who are winners, who are proven, then, yeah, let's go and get them," said Giggs.

"And with any good team the spine is important. Midfield, striker, centre-backs, goalkeeper. I'm sure we'll be looking to strengthen the spine all the way through.

"We obviously need to strengthen because we were fourth. We weren't first, second or third."

United have made one summer signing so far with PSV Eindhoven winger Memphis Depay joining for a reported fee of £25 million.

And Giggs tipped the 21-year-old to become a crowd favourite and set-piece specialist in the mould of David Beckham and Cristiano Ronaldo.

"He is the type Old Trafford will warm to," he added. "He's an exciting player, but there's also substance behind it. He was top scorer in the Dutch league and got plenty of assists as well. He's a 'United' type. Our fans demand exciting players, players who can get them off their seats and score spectacular goals.

"One thing we probably have lacked since Cristiano - and David Beckham before him - is free kicks. And it looks like Depay has a great track record from free kicks as well.

"Over a season, if you can score more from free-kicks and corners it adds up and makes a real difference in winning games. So, no pressure ... but hopefully he'll score 10 free-kicks every year."