Rafael Nadal will test out his new service action for the first time in his opening round clash with James Duckworth at the Australian Open on Monday.

The Spaniard has not played a competitive match since retiring from his US Open semi-final against Juan Martin del Potro last September due to pain in his knee.

An abdominal strain then prevented a comeback later in the season and he took the opportunity to have minor ankle surgery before a thigh issue saw him pull out of last week’s tournament in Brisbane.

But, amid all the physical challenges, Nadal and his coaching team of Carlos Moya and Francisco Roig found time to remodel his serving action in a bid to take some of the strain off the 32-year-old’s body.

Moya told atptour.com: “We’re looking to maximise damage from the onset, and one way to do that is with a faster, more aggressive serve.”

Nadal was happy to take on the challenge, saying: “You need to make you feel alive. There is always things to improve. The serve was always a thing that I tried to improve, and I think I did.

“Maybe it was the time to try to make one more step. That’s what we are trying. I happy with it. I’m happy with the motivation to do something new.

“I happy with the fact that, if I am able to make that happen in a good way, that hopefully will give me the chance to help me in my game longer term. I didn’t compete with this new serve, so let’s see how it works. I am confident it’s going to work well.”

Nadal gave a positive report on his fitness, adding: “I feel good. If I am not feeling good, I will not be here. I have good feelings in terms of the surgery that I had in the foot. I can say it is almost done.

“It’s again another season, coming back from a tough period of time, but with the highest motivation possible to start another season. I’m very excited to be back here in Melbourne.”

Nick Kyrgios was the leading Australian 12 months ago with a run to the fourth round but the rest of the season featured his now customary struggles with form, fitness and motivation and he goes into his home grand slam ranked outside the top 50.

Being unseeded cost Kyrgios in the draw when he was paired with Milos Raonic but he insisted he is in a good place after “seeking help” away from the court.

He said: “I really don’t want to touch too much on it. Pretty personal stuff that happened last year. I was in some really bad places. Right now I feel like I’m in a good spot mentally. People are going to think, ‘You drew Raonic, it’s a bad draw’. I don’t really care. I’m healthy, happy, go out there and compete. Whatever happens, happens.

“Realistically, one day it’s going to end for me, this sport. We saw Andy Murray, legend of the game, he’s not going to play any more. I take those things for granted how much I’m going to play grand slams. I’m just going to enjoy the moment. I’m not going to worry about anything. I want to be waking up, be excited to go on court. Last year I was not in that mind frame.”

Fourth seed Alexander Zverev, meanwhile, hopes a more relaxed approach could be the key to cracking the grand slam conundrum.

The German, who has only reached one slam quarter-final, claimed his biggest victory at the ATP Finals in November by beating Roger Federer and Novak Djokovic back to back having arrived at the tournament with low expectations.

He said: “Once I learn how to really enjoy it and really find fun in what I do, I think everything else will take care of itself.”