Ryan Giggs issues warning to Manchester United youngsters

Giggs has been a regular in the side this season (GETTY IMAGES)

Ryan Giggs has warned Manchester United's Carling Cup rookies they must show greater backbone if they are to succeed at Old Trafford.

Holders United surrendered their place in the competition with a 4-0 quarter-final drubbing by West Ham last night, their worst defeat for nine years and their first loss of the season.

A young side containing players such as Bebe, Chris Smalling and Javier Hernandez was swept aside as the Hammers defied arctic conditions at Upton Park to produce a sizzling display.

Home fans stayed behind to take photos of the scoreboard and even though it was a callow United side, Sir Alex Ferguson will have found the experience hard to accept.

Giggs, one of the few senior players in action, concedes that United wilted after West Ham's 22nd minute opener and again in the second half.

The Welsh winger believes they had the fight knocked out of them far too easily.

"Maybe heads can drop and the first goal came at a good time for West Ham," said Giggs.

"Obviously we started the second half really well, but they scored from their first attack and maybe heads dropped.

"But you are at Manchester United and you need to rise above that.

"You still need to carry on playing your football and not let your heads drop."

Giggs admits United paid the price for some feeble defending that saw Jonathan Spector score the first goals of his six seasons in English football against his former club.

England marksman Carlton Cole was on target twice after half-time, while the brilliant Victor Obinna set up all four strikes.

"It was disappointing to lose 4-0. We were confident that we could win the game and it was not to be," said Giggs.

"West Ham played well and you need to give some credit to them as they scored some good goals.

"But we feel that we could have defended the goals a lot better and it could all have been different had the first shot from Gabriel Obertan gone in.

"We started the game pretty well but Gabriel's effort did not fall for us.

"Instead it hit the post and they scored quickly after that.

"That probably knocked the stuffing out of us. Like I say, we could have done better for the goals."

It was the first time West Ham had avoided defeat by United in three years and Giggs insists Upton Park is traditionally a problematic destination for the Red Devils.

"I know from first-hand experience whenever we've come here, no matter how West Ham are doing, it's always a tough game," he said.

"They always want to beat us and the crowd really get behind the team."