But at that time he was still under 30 years old, in terms of stamina, it was a moment where cr7's stamina was still very fit, it would not be the same as 37 years now. 2011 and above was CR7's peak performance so I'm not surprised to see his achievements with mourinho. I feel he is not suitable for Serie A, previously he play for Juventus in Serie A but the results are still not as expected, yes maybe age is a factor cr7
Regardless of the speculation, I don't think Ronaldo will be in Serie A anymore, it's even more likely that next season he will still be at Manchester United.