Manchester United will be looking to strengthen their roster for next season's campaign and assistant manager Ryan Giggs said the club is on the search for "proven winners."

In a statement to the Sunday Times Giggs said, "If there are players available who are winners, who are proven, then, yeah, let's go and get them. 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," the 42-year-old added.

United already have been linked to a number of top players this summer and ESPN reported that they already have a bid rejected.

Sources told ESPN that United's bid for Real Mardid defender Sergio Ramos has been rejected and in a report by the Mirror, Manchester City is also looking to compete for the 29-year-old's signature.

Other players linked to a move to Old Trafford are Bayern Munich midfielder Bastian Schweinsteiger and Southampton midfielder Morgan Schneiderlin.

In a report by the Mirror, United already sealed a £25 million deal for Schneiderlin who will join the club on July 1 once the transfer window opens.

Schneiderlin will be the second signing for Manchester United manager Louis van Gaal this summer following the addition of winger Memphis Depay from PSV Eindhoven.

In his statement with the Sunday Times, Giggs expressed his praises to Depay.

"He is the type Old Trafford will warm to. He's an exciting player, but there's also substance behind it," Giggs stated.

"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," he explained.

The Manchester United legend also addressed Depay's impressive record of free kicks which the club missed when Cristiano Ronaldo and David Beckham left.

"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," Giggs also said.