Injured Federer pulls out of Davis Cup and Dubai

BERNE (Reuters) - Swiss world number two Roger Federer has withdrawn from next month's Davis Cup first-round tie against the United States due to a back injury.

"Unfortunately I have to announce that I will not be taking part in either the Dubai tournament of the Davis Cup tie in the States," Federer said in a statement released by the Swiss tennis federation on Tuesday.

"It was a very difficult decision for me because it means I will miss not only one of my favorite events on the Tour, but also the chance along with my team mates to reach the next round of the Davis Cup."

Federer said he had picked up the injury last year and had not had enough time to build up the affected muscles.

He played in the Australian Open in January and reached the final which he lost to world number one Rafa Nadal.

"I will now use the coming weeks for further rehabilitation, to be certain that I am fully fit again and ready for the rest of the season.

Federer had deliberately chosen not to play the opening round of the Davis Cup in recent years in order to concentrate on retaining his status as world number one.

His decision to play in this season's first round, following his toppling from the number one spot by Nadal, was seen as a major boost for Switzerland's chances of winning their first Davis Cup title.

"We hugely regret that Roger can not travel with the team to the USA," said team captain Severin Luethi.

"The health of every player is of course the most important thing however and we hope to have Roger back with us again in time for the next tie."

Luethi said he would nominate a replacement next week for the March 6-8 tie in Birmingham, Alabama.

Federer has a home in Dubai, uses the city as a training base and has won the tournament four times in the last six years.

(Editing by Ed Osmond)