Replacing Cristiano Ronaldo has proved tougher than Real Madrid expected

When Real Madrid sold Cristiano Ronaldo in July, fans and local media alike all asked the same question: how do you replace him?

Ronaldo was Real's all-time top scorer, notching up 451 goals in 438 games in all competitions. He led the club to four Champions League titles from the last five available and was invariably the man who dug his side out of a hole with a goal from nothing just when they most needed a hero.

The message from inside the club, however, was that they did not need to make a 'Galactico' splash in the transfer market, and that the answer lay within the team already. Gareth Bale, signed in 2013 for a then world-record 85.3 million pounds ($109.12 million) from Tottenham Hotspur following an extended public courting, had long been marked out by Real president Florentino Perez as the man to take over from Ronaldo.

It was also suggested that French forward Karim Benzema would be freed from the shackles many perceived the Portuguese had placed on him and finally be able to play as a central striker. Then there was Marco Asensio. The 22-year-old is arguably the hottest prospect in Spanish football and he was earmarked for a place in the front three. Goodbye to the 'BBC' (Bale, Benzema, Cristiano) trident, hello to the 'BBA'.

Things started well. Real enjoyed four wins and a draw from their first five La Liga games, with the trio netting eight of the 12 goals scored, while Roma were swatted aside in their Champions League group-stage opener. Bale looked the business, while Benzema threatened to become a goal-scoring machine.

However, following September's 1-0 win over Espanyol, Real had five games without a win –- a run in which they went eight hours and one minute without scoring. While youngster Asensio can be forgiven for having his ups and downs, Bale picked up one of the many injuries that have blighted his time in the Spanish capital and Benzema looked the shadow of a striker capable of leading the line for the European champions.

It was the kind of thing that never happened when Ronaldo was at the club. It is no coincidence that Real have endured their most barren run in terms of victories and goals since just before the Portuguese joined the club in 2009.

They have slipped to seventh in La Liga, behind newly promoted Valladolid, and the pressure is mounting on new coach Julen Lopetegui, who when he took over the club would have envisaged Ronaldo being a key part of his squad.

With Sunday's Clasico looming, the first for 11 years that will feature neither the Portuguese nor Barcelona's Lionel Messi, the onus is on Real to prove that life after Ronaldo does exist. A defeat would only intensify the storm clouds brewing over the Bernabeu.