Rafael Nadal’s return to action after more than a month out due to injury saw him lose to teenager Carlos Alcaraz in the Madrid Open quarter finals, but the 21-time grand slam champion always knew it would take some time for his “old machine” to fire up.

The Spaniard, sidelined by a rib injury at Indian Wells in March, hopes to build momentum in Rome before launching his campaign for a 14th French Open crown.

He has endured a string of injuries during a career spanning more than two decades and he said he needed time to get his body up to speed.

“When you’re six weeks without touching a racquet and having the chance to move your body... my body is like an old machine. To put this machine on again it takes some time,” Nadal told reporters before the Italian Open.

“It’s not the same when you’re 19 than when you are almost 36, with all the issues I went through in my career. You need to build again the confidence, your movements, then you start feeling comfortable with your tennis.

“It’s more about being confident with my movements, recover the speed, recover the way that I have to play on clay and let’s see. I’m confident that I can play well. I need time, but maybe this week can be a positive week, maybe not. Who knows?”

Nadal, a winner of three titles this year, lost to Novak Djokovic in the Roland Garros semi-finals last year, just the third time he was beaten at the claycourt major since his debut there in 2005. The Spaniard said he was doing all he can to be fully ready for the tournament.

“That’s my goal... I didn’t have another chance to approach this claycourt season with the things I went through,” he said. “I’m going to give myself a chance and we'll see what’s going on.”

With his 36th birthday just a few weeks away, Nadal knows his body better than anyone, and also knows what he’s been through to remain at the top despite numerous injuries over the years.

The Spaniard’s brilliant start to the season, which saw him with a record 21st grand slam title in Australia and then reach the final in Indian Wells, was curtailed by a fractured rib and on his return to action last week in Madrid, he was short on preparation and confidence, losing out to eventual champion Alcaraz in the quarter finals.

The Italian Open offers Nadal a chance to build some momentum as he heads towards Roland-Garros. But even for someone as good as Nadal, hitting top form is not going to happen overnight.

Back at a tournament which he has won a record 10 times, Nadal said: “I am confident that I can play well honestly, no? The only thing that is sure is that I am going to keep trying and keep building confidence to try to be ready for next week, for the next two weeks.”

Asked if the tennis landscape is changing with the emergence of new players, Nadal told ATP Tennis TV, it's a "normal cycle of life."

(Written with inputs from Reuters)