Carlos Alcaraz expects Rafa Nadal to perform at a "spectacular level" at the French Open if the 14-times champion can overcome his injury issues ahead of the year's second Grand Slam.

Nadal skipped the ongoing Madrid Open after a setback in his recovery from a hip injury sustained at the Australian Open in January. The 22-times major champion also missed tournaments at Indian Wells, Miami, Monte Carlo and Barcelona.

Alcaraz has emerged as favourite for Roland Garros after victories on clay at Buenos Aires and Barcelona but the world number two said Nadal cannot be written off and hopes his fellow Spaniard will return next week in Rome.

"Hopefully he will be in Rome and then at Roland Garros, where he will be a rival to beat," Alcaraz told reporters after beating Alexander Zverev 6-1 6-2 on Tuesday to reach the Madrid quarter-finals.

"Although he hasn't played since Australia, a man who has won a tournament 14 times will always be difficult to beat in that tournament, even if he comes without match rhythm.

"It'll also be difficult for him, tennis requires that competitive rhythm, but Rafa is Rafa, even if he arrives without many matches, he'll surely show a spectacular level."

Alcaraz, who turns 20 on Friday, said reports of Nadal's return were encouraging as he hoped to continue learning from the 36-year-old. "I say this as a player and as a tennis lover," Alcaraz said.

"It's been a pity all these months where we haven't been able to see him in tournaments."