Cristiano Ronaldo's form a major concern for struggling Real Madrid

Cristiano Ronaldo's dry streak is becoming a concern. His lack of goals has left Real Madrid in a lowly position in the table, 16 points back from leaders Barcelona. 

Against Villarreal he had 11 shots, four on goal and seven off target, but was unable to find the back of the net, as Madrid were eventually beaten 1-0. 

Zinedine Zidane has no explanation for his side's lack of goals in a game they did not deserve to lose. 

Ronaldo is struggling in La Liga. His dry streak has left him with four goals in 14 appearances, his worst figures in nine seasons since he joined Madrid. 

In the past his goal scoring rate has nearly always been more than a goal a game, but he's currently scoring one goal every 314 minutes in Spain's top flight. 

WORST NUMBERS IN la LIGA

Ronaldo's converted just 4.55 percent of his chances in this negative run. He's had 94 shots on goal in La Liga, 32 on target, a total of 12.5 percent. 

The Portugal forward is racking up his worst statistics ever in a white shirt and beating records which he doesn't want to beat. 

Age could be a factor. He turns 33 in February and doesn't have the power, speed and resistance he had early in his career, with his market value in freefall. 

Ronaldo is no longer the forward that can make the difference when he's most needed, although he's continued to do well in the group stages of the Champions League. It remains to be seen if he can have an affect in the latter stages, though, when Madrid meet Paris Saint-Germain.