Cristiano Ronaldo with the Ultimate COVID Flex, Mansion and Muscles!

Nobody seems more content with COVID than Cristiano Ronaldo ...

The 35-year-old soccer superstar -- who was ordered to self-isolate earlier this week after testing positive -- is now chillaxing in his mansion in Turin, Italy like he doesn't have a care in the world.

As we previously reported, the Portuguese Football Association announced Ronaldo's positive test on Tuesday -- and said he had been sent home to prevent exposure to other Team Portugal players and staffers.

Well, home for CR7 is a massive estate with an indoor pool.

He's still smiling. He's still ripped to shreds. And, he's offering up encouraging words to his fans.

"Don't let what you can't do stand in the way of what you can do," Ronaldo said Friday on IG.

Ronaldo reportedly flew from Portugal to Italy on a private "air ambulance" which he paid for himself.

While Ronaldo has not personally commented about his health since the positive COVID test -- the Portuguese Football Federation said he was "well, without symptoms, and in isolation."