Cristiano Ronaldo seems to be unhappy....

He is so frustrated as could see Barcelona move four points clear at the top of La Liga.

Ronaldo's scoring exploits at the start of the season were scarcely believable, as he hit 25 goals in his first 14 league games to put himself well on track to smash La Liga's scoring record.

Since the start of 2015, however, his form has nosedived and he heads into Sunday's Clasico with just five goals in his last 10 league outings, having failed to register even a single shot on target in four of them.

The decline started on 10 January when he failed to score in a 3-0 victory over Espanyol. It was his first goalless home league game for 15 months and his frustration at ending that sequence was plain to see when he reacted with melodramatic horror after Gareth Bale shot rather than passing to him, sparking a drawn-out debate over whether or not the Welshman is selfish.

This might be the reason why He seems to be so angry...

Long-standing team-mate Sergio Ramos believes Ronaldo's dark mood is explained simply by his recent lack of goals. "He's used to scoring 60 goals a year and when he gets 40 he's not happy - he has a very competitive character," said Ramos.

Ramos is, no doubt, correct to suggest that his team-mate's failures in front of goal are the prime source of his discontent. His ambition to be lauded as the world's greatest is well documented, and it's easy to understand how such a relentless obsession can easily spill over into introspective self-indulgence.