The 36-year-old has recently stated in an interview with Sky Sports News that every Red Devils player "can do better" and he will not accept the club finishing lower than third in the Premier League.
Ronaldo has endured a frustrating return to Old Trafford, with one previous report claiming that the forward's arrival has caused tension in the dressing room and that 'several small cliques' have formed as a result.
Now, The Sun reports that a number of United players are wary of making mistakes or failing to execute the correct pass to Ronaldo because of the negative reaction they might get from the five-time Ballon d'Or winner.
The report also claims that Ronaldo is quoted to have told United's younger players: "If you don't want my help, do your job."
United's first-team players are allegedly used to enjoying less intense and competitive training sessions in comparison to Ronaldo, who is keen to adopt several methods used previously by club legend Sir Alex Ferguson.
After missing the FA Cup win against Aston Villa on Monday due to injury, Ronaldo has revealed that he hopes to be back in contention for United's Premier League trip to Villa Park on Saturday. body check tags ::