Andy Murray has pulled out of Great Britain's Davis Cup tie against Argentina in Buenos Aires next week because of a recurring knee problem.
Murray was out for almost three months in 2007 with a wrist problem
The 20-year-old, who lost in the first round of the Australian Open, has been struggling since he returned home.
"We had a scan done this week and have decided that it is better not to play.
"Experts have advised me that going from hard courts to clay and back to indoor courts could increase chances of further injury," he told his website.
Murray dropped out of the world's top 10 after he was beaten in Melbourne by Frenchman Jo-Wilfried Tsonga, who went on to reach the final.
Last year I learned about the importance of looking after my body and I don't want to make any mistakes going forward
The Scot won the Qatar Open in the lead-up to the first Grand Slam tournament of the year and insisted his defeat by Tsonga was not down to physical problems.
The British number one, who missed almost three months with a wrist problem last year, spent the off-season working in Miami with fitness experts Jez Green, Matt Little and Miles Maclagan.
Green admits the intensity of the workouts may have backfired.
"Andy's workload in the off-season was incredibly high and put a lot of stress on the right knee.
"This is causing him some problems on certain movements. Changing surfaces three times in such a short time span would be a great risk to further injury."
And Murray added: "Last year was very difficult with my wrist injury. I learned about the importance of looking after my body and I don't want to make any mistakes going forward.
"Taking this preventive measure is a very difficult decision but because I didn't play a full year last year, the next two months are very important if I am to maintain my chances of challenging the top players."
Murray's withdrawal is a massive blow to Britain's chances of success in their World Group first-round tie - their first in the elite section after a four-year gap.
Our chances are now not exactly rosy but we'll do the best we can
Alex Bogdanovic is their next highest ranked player at 187, while Argentina will be led by world number 10 David Nalbandian.
Doubles specialist Ross Hutchins has been named as the fourth member of the GB team, joining Andy's brother Jamie, Bogdanovic and Jamie Baker.
Team captain John Lloyd told BBC Radio 5 Live: "We're not very happy but these things happen. I'm actually really sad for Andy because I think he's missing out on an unbelievable occasion.
"He could have gone up against some of the world's best in an environment that's going to be hostile, to put it mildly, and would have a chance to prove how good a player he really is.
"I think he would have really enjoyed that task. I'm sad for him that he's not going to be here and I'm sad for the team because he's our number one player.
"Our chances are now not exactly rosy but we'll do the best we can."