Cristiano Ronaldo told Manchester United board he would leave if Ralf Rangnick remained as manager

Ralf Rangnick and Cristiano Ronaldo earlier this season (Photo by Sebastian Frej/MB Media/Getty Images)

Cristiano Ronaldo warned Manchester United’s board that he would leave the club at the end of the season if Ralf Rangnick was appointed manager on a permanent basis.

The German took interim charge of the Red Devils in December,…