Cristiano Ronaldo enduring worst form in 11 years with Ralf Rangnick running out of road

It speaks volumes about Cristiano Ronaldo 's sustained brilliance that a five-game drought is a crisis.

But there is no denying the Manchester United talisman has failed to live up to the world-class standards expected of him since the turn of the year.

Ronaldo, 37, has not found the back of the net since the 3-1 victory over Burnley in late December, and the Clarets themselves were the latest team to frustrate him in a 1-1 stalemate on Tuesday night.

The Portuguese striker dropped out of the starting XI for the trip to Turf Moor and was introduced midway through the second half, struggling to make an impression in the search for a winner after Jay Rodriguez cancelled out Paul Pogba's opener.

Ronaldo made straight for the tunnel at the full-time whistle, which not only marked two points dropped for United, but also an unwanted milestone for the five-time Ballon d'Or winner.

Having also failed to score in January's Premier League clashes against Wolves, Brentford and West Ham, as well as last Friday's FA Cup tie with Middlesbrough, Ronaldo is without a goal in five appearances.

Astonishingly, this is his longest barren run at club level since his early days at Real Madrid, when he went five games without scoring between May and September 2010.

Although he was benched against Burnley, Ronaldo started the other four games during his current troublesome spell and played 120 minutes against Middlesbrough before United were defeated on penalties.

He converted his spot kick in the shootout but crucially missed from 12 yards just 20 minutes into the fourth-round encounter.

Ralf Rangnick hinted Ronaldo's exertions against Middlesbrough contributed to the decision not to start him against Burnley, emphasising the