Maurizio Sarri helped Ralf Rangnick identify new Cristiano Ronaldo issue at Manchester United

Manchester United's reunion with Cristiano Ronaldo has not gone the way that either party would have hoped.

Since the appointment of Ralf Rangnick, the forward has only scored two non-penalty goals with another coming from the spot and overall in the league, he has failed to be the driving force to win United the league that many pundits claimed he would be. His enforced absence from the starting XI that lost 4-1 at Manchester City offered a suggestion of what life without the Portuguese would look like.

United's galling derby-day defeat has left Ralf Rangnick's side 22 points behind leaders City and the gap between themselves and City and Liverpool is vast. So where has it gone wrong - and what role does Ronaldo play in this?

Some have pointed to the obvious factor of Ronaldo's age, at 37 he is no longer somebody with the same youthful exuberance he once possessed and while a decline in his physical ability seems very likely, there are ways to mitigate this.

Many fans have suggested that Ronaldo has used his goalscoring ability to become more of an in-the-box poacher and his deployment as a lone number nine in a 4-3-3 under Rangnick seems to lend to this idea. The suggestion probably comes from the success that Edinson Cavani found in this role last season.

But when Ronaldo plays you see his reluctance to take up this mantle.

He drifts into the wide spaces and wants to pick up the ball outside the box, instead of moving into the space and looking to get on the end of crosses and passes into the box from Jadon Sancho, Bruno Fernandes and Anthony Elanga.

But his former coach Maurizio Sarri, who managed the player at Juventus may have provided the answer. In an interview with Sky Italia, he said: "Cristiano scored