The Monaco boss says the Colombian is progressing well in his recovery from a knee injury and has dismissed rumours he is set to leave the club
The 28-year-old has been out of action since January after sustaining knee ligament damage and warned last month that he would not rush his comeback simply to force his way into Jose Pekerman's squad for Brazil.
Ranieri, however, says the former Atletico Madrid striker has been progressing well in his rehabilitation and believes he has an excellent chance of making the tournament should his recovery continue unabated.
"Falcao is incredible. He is sharper than before. He's running and it's going well. If he continues like this, I think he'll be able to play for Colombia at the World Cup, but unfortunately not for us before the end of the season," he told Canal Plus.
Rumours emerged last week that Ranieri's position at the Stade Louis II could be under threat but the Italian coach says he will not pay any heed to the rumour mill.
"Talk about my future? That's normal, football is like that. These are just rumours. I'm very happy here," he said.
"The president is pleased with my work. I'm certain I will be here again next season."
Monaco attacker James Rodriguez also stressed he would be eager to see Ranieri at the club for next season and admitted Colombia would be a far stronger side should Falcao be fit for Brazil.
"I hope Falcao will be available for the World Cup. We need him. He is so important for us," James added.
"We're not surprised by the rumours about Ranieri. If he stays, it will be good for me, because he is a coach with a lot of experience."