Nadal is currently preparing for the 2019 clay court season at his academy in Mallorca.
And despite the threat of world No 1 Novak Djokovic, Nadal remains the man to beat on the red dirt.
The Spaniard has won at the French Open, Monte Carlo and Barcelona Open 11 times and the Rome Masters on eight occasions.
And between April 2005 and May 2007, he won 81 consecutive matches on clay.
Nadal is comfortably the greatest player to ever play on clay in the history of tennis.
And Franulovic believes the variety in the men’s game means there will never be a specialist like Nadal on clay.
“There will be not a Nadal’s heir as a player or character”, Franulovic told website We Love Tennis.
“It’s impossible to find a new Nadal on clay.
“There are less clay-courts specialists, on the contrary of what you could see in the past with Spaniards or Italians.
“The current Tour makes you flexible.
“[Novak] Djokovic plays well on clay the way he does on hard or grass, as well as [Alexander] Zverev and [Dominic] Thiem as well who just won in Indian Wells.”
Speaking in an interview on Radio Marca, David Ferrer issued an injury update on his compatriot.
And revealed he expected Nadal to be as strong as ever during the clay season.
“I think Rafa has recovered well and has been able to rest,” he said.
“If he does not have any injuries he will be the big favourite on clay but also on a fast track.”
“Nadal has had bad luck with injuries that have reduced him in many important tournaments.“