Andy Murray will miss Great Britain's Davis Cup tie against Slovakia in Glasgow next weekend in order to recover from "a few minor injuries" picked up in Australia.
The British number one's decision is a big blow to Britain's hopes of securing victory on their return to Europe/Africa Zone Group I, with James Ward now the GB number one and Dan Evans coming in alongside doubles pair Colin Fleming and Ross Hutchins.
Murray said: "I've been told to take a few weeks off after picking up a few minor injuries in Australia.
"I'm gutted to miss out on the Davis Cup having really enjoyed playing last year, but as it's only the start of an important season, which includes the Olympics in London, it's probably a sensible decision.
"My focus in 2012 is on performing well in the grand slams and the London 2012 Olympics. I look forward to playing in the next Davis Cup tie later in the year."
Murray was affected by a knee problem on his way to victory in the Brisbane International earlier this month and was then pushed to the limit in a near-five-hour semi-final defeat by eventual champion Novak Djokovic at the Australian Open last Friday.
Murray is scheduled to return to ATP World Tour action at the Dubai Duty Free Tennis Championships at the end of February and new coach Ivan Lendl is keen for him to head out to his training base in Miami before then.
The 24-year-old took a break from Davis Cup in 2010 but returned in last July's win over Luxembourg and also played in the 5-0 win over Hungary in September that earned Britain promotion back to the second tier of the competition.
Murray had voiced doubts about his participation this time around because of the changes made to the calendar to accommodate the Olympics, with the Davis Cup weeks brought forward from the usual March and July to February and April.
Ward has proved himself a very valuable member of the team over the past couple of years, winning seven singles rubbers and losing only two, and he goes into the tie on a high after qualifying for the main draw of a grand slam for the first time in Australia.
Fleming and Hutchins, meanwhile, have developed into an impressive doubles partnership and were quarter-finalists at Wimbledon and the US Open last year.
The tie represents a big opportunity for Evans, who has not played Davis Cup since losing both his singles matches in the defeat by Lithuania in March 2010, the low point of Britain's slide down the standings.
The 21-year-old from Birmingham has yet to win a Davis Cup rubber but he has been showing encouraging form, winning a Futures title earlier this month and this week qualifying for the main draw of the ATP World Tour event in Zagreb.
Evans is still only the British number five and his ranking of 296 and Ward's 155 do not compare favourably with Slovakia, who will be represented in singles at Braehead Arena by world number 97 Lukas Lacko and number 116 Martin Klizan.
Their doubles pairing of Filip Polasek and Michal Mertinak, meanwhile, have between them won 20 titles on the ATP World Tour.
GB team captain Leon Smith said: "This is a real step up in standard for the team and we go into the tie knowing the Slovak Republic will be favourites.
"But I am confident the boys will see this as a great chance to put everything into representing their country and that with the backing of a fantastic set of home fans we can upset the odds."
Victory would send Britain through to a promotion play-off with Belgium in April for the chance to get back into the World Group while defeat would mean a relegation play-off to stay in the second tier.