• ‘I have all of December to put my body at the right level’ • Nadal misses ATP World Tour Finals after appendix removal • Nadal hits out at Spain’s female Davis Cup captain

Rafael Nadal, the former world No1, is confident he will be able to return to full fitness for the 2015 Australian Open.

The 28-year-old Spaniard is recovering from surgery to remove his appendix which saw him miss the season-ending ATP World Tour Finals in London last week.

Nadal has also battled knee, wrist and back problems, with his doctors confirming his rehabilitation included stem-cell treatment.

The 14-time grand slam champion, though, feels positive he can return to competitive action in time for the first major at Melbourne Park, where he lost the 2014 final against Stan Wawrinka. “It will be 10 or 12 days before I can practise again, so [I] will have all of December to try to put my body and my tennis at the right level to be competitive in January. I am going to work for it, that is my goal,” said Nadal.

“I hope to be healthy enough to work as much as I need, and as I want, if that happens I really feel confident I can come back strong.”

Nadal continued: “During this year I had some periods when I had some problems in my back. During these months, I did not have the chance to compete with all of the things which happened to me. I have time enough to fix my back 100% again.

“When you have been out of the tennis court for two months, when you practise again on the first day, you will not be 100%. But the most important thing is I will be healthy to increase the practice every day and can then be around 100% by the eighth of December then have one month to practise at 100%.

“I try to fix my level of tennis, all of the things you need to come back strong. I will have a few days at an exhibition [event] in Abu Dhabi, which will help me arrive at the first official [ATP] competition of the year [2015] in Doha with normal conditions, being competitive.

“If that happens, then you can start increasing the level in every single match.”

Nadal felt the ATP World Tour Finals had been “strange”, with The O2 Arena crowd denied the chance to watch a showdown between Roger Federer and Novak Djokovic after the Swiss player retired injured.

“I saw a little bit, but not a lot, the matches were too quick to see,” said Nadal, who had “no opinion” on the reported row between Federer and his Davis Cup team-mate Wawrinka, who are said to have clashed following a tense semi-final.

“It was a really strange World Tour Finals, the strangest ones I have ever seen – normally when you play between the best eight players in the world the matches should be close and be emotional. In this tournament no one match was like this, only Roger against Stan in the semi-finals – but for the rest it was a little bit strange.

“The only thing which is negative is for a tournament in London to have no final is bad news for everybody, for the tournament, for the fans, for all the world of tennis, and especially for Roger. I wish him a quick recovery.”