“I am fine. I had a little problem in training, a dead leg as they say here, but tomorrow or the next day I will be fine,” he said.
Ronaldo will be aiming to break his own record of 17 Champions League goals in a season in Milan having already netted 16 in the competition so far this campaign.
His 17th two years ago came in the final against Atletico as Real ran out 4-1 winners after extra-time.
“It would be nice to equal or even pass the record, but I am not obsessed with that because the most important thing is to win,” he added.
And Ronaldo insisted Real will show they are the kings of the Spanish capital once more despite winning just once in 10 games against Atletico since lifting their 10th European Cup in Lisbon.
“We will see who is the best. I am positive. I think Real are better than Atletico, but we have to show it on the pitch.”
To do so Real must break down a rock solid Atletico defence that has kept 35 clean sheets in 56 games this season, including shutouts at home to Barcelona and Bayern Munich in dumping the Spanish and German champions out at the quarter-final and semi-final stages respectively.
Atletico also managed a 1-0 win at Real’s Santiago Bernabeu to inflict Real coach Zinedine Zidane’s only La Liga defeat in four months in charge when the sides last met in February.
“Atletico always play the same way. We know there will be very few opportunities because they all play behind the ball,” continued Ronaldo.
“It is no coincidence that Barca and Bayern couldn’t score many goals against them.”
Ronaldo has been dogged by a persistent thigh injury which forced him to miss three games last month.
He also came off at half-time of Real’s final La Liga game of the season — having scored twice in the first-half to take his tally for the season to 51 — at Deportivo la Coruna 10 days ago.
Zidane confirmed Ronaldo also didn’t play in a practice match on Saturday as a precaution, but expects him to be fully fit for the final.
“There will be no problem. He felt something on Saturday when we had a game between us and he didn’t play as a precaution,” said Zidane.
“He will be ready for Saturday and I think we are in good shape physically.”
However, there isn’t such good news for French defender Raphael Varane as Zidane confirmed he will miss Saturday’s final and his participation at Euro 2016 is now in jeopardy due to a hamstring injury.
Varane was unlikely to start at the San Siro in any case with captain Sergio Ramos and Pepe Zidane’s preferred central defensive partnership.
An 11th European Cup would cap a sensational start to Zidane’s senior management career having turned around Real’s fortunes with 21 wins from 26 games since replacing the sacked Rafael Benitez in January.
“I think everybody feels the fun comes back a little bit when he arrived,” said Real midfielder Toni Kroos.
However, the Frenchman — who won the Champions League for Madrid with a sensational volleyed winner in the 2002 final — insisted he still has a lot to learn as a coach.
“I have a lot to learn, the desire I have to learn is tremendous and I am convinced I am going to improve,” said Zidane.
“I have a lot to do to be a good and important coach in football.”
And Zidane rejected Ronaldo’s assertion that Atletico’s success in reaching a second Champions League final in three years is solely due to their defensive record.
“It will be a difficult game because we are playing against a team that doesn’t just defend well.
“Everyone talks about them defending well, but they are a complete team. They can also cause you problems playing with the ball.”