Barca missing tactical nous of convalescing coach Tito Vilanova

Barcelona's King's Cup elimination at the hands of Real Madrid raised the question of just how much they are missing coach Tito Vilanova, while he continues his recovery from throat surgery in New York.

Although they exercised their customary domination of possession, Barca again looked short on ideas in the final third of the pitch and Real strolled to a 3-1 victory at the Nou Camp that put them through to May's final 4-2 on aggregate.

Cristiano Ronaldo became the first player to score in six straight "Clasicos" away from home when he picked himself up after being felled by Gerard Pique in the 13th minute and struck a powerful low penalty into the corner past Jose Manuel Pinto.

Barca dominated possession but rarely threatened and Ronaldo doubled the lead when he collected a rebound from a 57th-minute Angel Di Maria effort and stroked the ball calmly into the net with Pinto stranded.

Real rubbed salt in their rivals' wounds when Raphael Varane rose at a 68th-minute corner and sent a header arrowing into the net off the crossbar.

Jordi Alba pulled one back in the 89th minute but it was far too late for Barca, who conceded three goals to Real at home for the first time since a 3-3 draw in March 2007.

Jose Mourinho's side, organised in defence and clinical in attack, appeared to find it just as easy to keep Barca at bay as AC Milan did when they beat the Catalans 2-0 in last week's Champions League last 16, first leg.

However many passes Xavi, Andres Iniesta, Sergio Busquets and their teammates strung together they were too predictable and were unable to provide Lionel Messi with the service that has made the World Player of the Year such a lethal goalscorer.

Vilanova, who stepped up from assistant coach to succeed Pep Guardiola at the end of last season, needed a second round of surgery in December following an operation to remove a tumour from his saliva glands in November 2011.

His assistant Jordi Roura has temporarily taken over and although the pair are in constant contact there is little doubt that Vilanova's absence is felt.

The contrast with Real is significant. Mourinho brings the authority of a two-times Champions League winner who has experience across Europe to their bench while Roura, a former Barca player, has never had a top coaching job.

"Without taking anything away from the work of the rest of the coaching staff there is no doubt that we miss Tito Vilanova," Barca president Sandro Rosell said. "He is our coach, our leader.

"Imagine any institution, any company, any factory without their chief of production.

"That's why it's important that we visit him and check how he is getting on.

"The priority is his health ahead of any match, any victory and any trophy that we might want to have in our cabinet."

Barca's bid to repeat their 2009 treble of titles in the Champions League, La Liga and King's Cup is now over and they face a tough task in overturning the two-goal deficit at home to Milan on March 12.

However, they appear to have a fourth La Liga title in five years within their grasp.

They are 12 points clear of second-placed Atletico Madrid ahead of Saturday's trip to play champions Real at the Bernabeu with Mourinho's side a further four points back in third.