Rafael Nadal doing extra fitness "like a little bit of pre-season" as Roland Garros prep ramps up

WATCH: Nadal speaks with press in Madrid

Rafael Nadal says he is fully recovered but lacking practice and training as he returns to competition this week in Madrid.

The 35-year-old started this season on a tear, winning the Australian Open, Acapulco and Indian Wells, but experienced a rib injury at the BNP Paribas Open that has sidelined him for six weeks.

The setback is no longer a problem, he confirmed.

"No, I'm good physically in terms of the rib. I have been doing tests every single week," Nadal said during his pre-tournament press conference. "If I come here, it's because the doctors tell me I have no risk at all."

But though all he needed was rest, the injury prevented him from doing even basic physical activities and has left him behind in his fitness.

"[There were] a lot of difficulties, even to fall asleep even because of the pain, but after that, little by little I was able to go a little bit to the gym," said Nadal. "It's been a period that I haven't been able to do a lot of things. So as you can imagine, it's been six weeks of which I started to train two weeks ago."

Nadal, who came into this season having already been off the tour for five months with foot problems, is now looking to get back his level of play as he looks for another record-extending French Open title in a few weeks. Having done it often in his career, the 13-time winner knows what is required.

"But I hope to have it back in a couple of weeks if I am able to practice with the right attitude and with humility, to accept the challenge and to accept that there [is] gonna be days [where] the things are not going the right way," said Nadal. "I'm doing a double session of training today, the day before yesterday too, and I'm trying to face these days like a little bit of pre-season."

Nadal, the third seed, will start his Mutua Madrid Open campaign Wednesday in the second round against Miomir Kecmanovic.