Ronaldo has been in the Spanish capital since leaving Old Trafford in 2009 and it has been reported that Mourinho urged United not to re-sign the forward.
The pair worked together at Real Madrid and will come head-to-head in this season’s Champions League group stage.
‘The objective is clearly to win the Champions League, which they were close twice when they reached the final, so they are a top team in Europe that made one of the biggest spending – I think after Liverpool it must be them.
‘Fantastic players – Cristiano, (Emre) Can and (Leonardo) Bonucci. Absolutely top.
‘But they are going to have two very difficult matches against us.
‘Cristiano was never on my table to say “yes” or “no” to Cristiano to come to us. It was never on the table.’