Roger Federer has pulled out of Switzerland's Davis Cup series against the United States and the Dubai Tennis Championships to aid his recovery from a back injury.
In a message on his website on Tuesday Federer said it was a precautionary measure as he had not had enough time to strengthen his back after it was injured last year.
"This decision was very difficult for me, because I won't just be missing one of my favourite tournaments of the tour, but also the chance to go through to the next round with my teammates," he said.
He said he would be using the coming weeks for further rehabilitation in order to ensure that he was fully fit for the rest of the season.
Switzerland faces the US in the first round of the Davis Cup on March 6-8 in Birmingham, Alabama. The Dubai tournament starts on February 25.