The Portuguese Football Federation announced that Ronaldo had tested positive for coronavirus on Tuesday afternoon.
Ronaldo will have to be completely Covid-free for one week before returning to action, which puts his participation in a Serie A meeting with Verona and a European showdown with Barcelona at the end of the month in doubt too.
Santos has delivered an update on the talismanic figure's condition as he continues to prepare his side for the trip to Sweden on Wednesday.
The 66-year-old head coach acknowledges the fact Portugal will be weaker without Ronaldo, but says he is still in good health and high spirits after contracting the virus.
"No team can be better without the best player in the world but this team has already demonstrated that collectively it has the capacity to tackle the situation," Santos told a press conference of Portugal's captain.
"He is managing the situation very well. He is in the room, saying he wants to play, he talks to us from upstairs [from his balcony].
"He is completely asymptomatic, he is okay, without any symptoms, he doesn’t even know what happened to him."
Asked how Portugal will cope without Ronaldo against Sweden, Santos responded: "Any player who is absent due to Covid-19 is a big loss, and Ronaldo’s absence is probably even greater [than anyone else’s].
"But I have absolute confidence in those players who are going to play.
"The plan is the same. But the dynamics are different. Cristiano has his own characteristics. No team is better without the best player in the world.
"But this team have already shown that they have the ability to respond as a collective. I have full confidence in my players."