The Real Madrid winger is hoping the former Atletico striker makes a rapid return from injury as he would love to see the Colombian in Brazil this summer.
The Monaco forward, 27, has been ruled out for the remainder of the season after tearing his anterior cruciate ligament earlier in January, seemingly ruling the Colombia international out of this summer's tournament in Brazil.
However, the doctor who operated on the former Atletico Madrid man has claimed he could recover in time for the World Cup and Real Madrid's Ronaldo is hoping Falcao is able to return in time to grace the game's grandest stage.
"The only message I can give him is that I know he has so much strength and courage," the Portugal international told RCN. "I hope that he recovers very fast because football needs Falcao.
"The World Cup and the Colombia team await him. I hope he recovers soon and can return to action in time. It's what we all want. Stay strong, Falcao."
Falcao was one of La Liga's star players before his mega-money move to Monaco in the summer and he went head-to-head with Ronaldo on a number of occasions during his two-year stay at the Vicente Calderon.
If the Colombian does pull off the unlikely feat of regaining fitness in time for the World Cup, the striker and his teammates will face Japan, Cote d'Ivoire and Greece in Group C.