Navas rose to fame in La Liga last season for a string of spectacular performances for Levante.
The 27-year-old put in particularly impressive displays against Barcelona, Atletico Madrid and Valencia and pulled off numerous eye-catching stops in Costa Rica's surprise 3-1 win over Uruguay on Saturday.
Navas, one of a host of ex-Saprissa men in the Costa Rica squad, has been in Spain since 2010 when he – like goalkeeper Conejo before him – joined Albacete, but he is expected to leave Levante after the World Cup.
A move to Atletico has been mooted by some as the Liga champions eye a replacement for Thibaut Courtois, who looks set to return to Chelsea, and Conejo believes the stage is set for Navas to emerge as a global talent.
"He (Navas) will surpass me," claimed the 1990 World Cup star. "Today, goalkeepers are formed differently. In our time there was no specific training.
"It was only natural (ability). But, that part of it, he (Navas) has. He has important natural abilities and features. To me, he's going to fight to be the best goalkeeper in the world.
"When I saw him for the first time, Keylor was young and small. He ended up not being among the (picked) goalkeepers.
"But then we started working with other selections. He is a keeper of special features. He's fast, powerful and complete.
"He knows how to work with his feet, something which is required in football today. He reads the game very well, moves well and is explosive."
'Obviously Messi is the best player in history and being compared to him means that you're doing things right, but I try to be myself': Barcelona star responds to comparisons with Argentine legend
'Darwin Nunez would be gold for Arsenal': Liverpool legend claims Gunners should have signed Uruguayan striker in January
