(CNN) -- Rafael Nadal has sent shockwaves throughout the tennis world after withdrawing from the Australian Open.
The 11-times grand slam champion, who reached the final in Melbourne last year, had been expected to make his comeback from injury next month.
Nadal's withdrawal means he will slip out of the top four for the first time in over seven years.
After pulling out of an exhibition tournament in Abu Dhabi this week with a stomach infection, Nadal was still expected to compete at the ATP event in Doha before making his way to Australia.
The 26-year-old, who has not played since his shock second round defeat by world number 100 Lukas Rosol at Wimbledon, had hoped to make a return to action following a six-month absence with a knee injury.
But a virus has forced Nadal to pull out of both Doha and the Australian Open following discussions with doctors.
He said: "My knee is much better and the rehabilitation process has gone well as predicted by the doctors, but this virus didn't allow me to practice this past week and therefore I am sorry to announce that I will not play in Doha and the Australian Open, as we had initially scheduled.
"As my team and doctors say, the safest thing to do is to do things well and this virus has delayed my plans of playing these weeks.
"I will have to wait until the Acapulco tournament to compete again, although I could consider to play before at any other ATP event.
"I always said that my return to competition will be when I am in the right conditions to play and after all this time away from the courts I'd rather not accelerate the comeback and prefer to do things well."
Nadal has endured an injury-ravaged year, missing out on defending his Olympic title at London 2012 as well as sitting out the U.S. Open and Spain's Davis Cup final defeat in November.
Coach and uncle Toni Nadal believes his nephew was left with little choice but to cancel his plans to compete in Melbourne after contracting the virus.
He said: "We consider not appropriate to play the Australian Open since we will not have enough preparation for a greater competition which is a Grand Slam tournament.
"It is simply not conceivable that his first event is a best of five sets event, he wouldn't be ready for that.
"It is true we have been quite unlucky with this but there is nothing we can do.
"After all this time it is better to do things well and the most professional thing to do is to start when we are ready."
While the Nadal camp is understandably saddened by the news, it will also leave his fellow professionals disappointed.
World number one, Novak Djokovic, who beat Nadal in Melbourne last year, was looking forward to facing his old adversary once again.
"I was eager to see him play," said Djokovic.
"He has been off the tour for the past seven months and I am sure that all tennis fans and all sports fans want to see him back on the court, healthy and fit.
"I wish him, as a colleague, a fast recovery.
"It's unfortunate and I'm sure he feels the biggest need to play tennis out of everybody and hopefully he can bit for the Australian Open which is the most important experience."
Meanwhile, Djokovic started his own season in style with a 6-0 6-3 win over Ferrer.
The Serbia star, who won the tournament last year, cruised through the first set before Ferrer began to offer resistance in the second.
Ferrer, ranked five in the world, led 3-1 in the second before Djokovic roared back to take the set.
"I love this court and the conditions here. I wish all the tournaments in the world were played here," Djokovic told ESPN.
"It's definitely a great surface. It's not too warm here, not too cold, it's ideal to prepare on.
"I am surprised with my game considering it's the first match of the official season. Hopefully I can play another good one tomorrow."
Djokovic will meet Nicolas Almagro in the final after the Spaniard came from a set down to defeat Janko Tipsarevic 2-6, 7-6, 6-2.