Safin's injury is more serious than first thought

Marat Safin will miss the start of Russia's Davis Cup defence against the Czech Republic.

The world number three injured his left wrist at the Australian Open and was forced to withdraw from his third-round match against German finalist Rainer Schuettler.

It was thought Safin would recover in time for the first round World Group tie.

But Russian tennis chief and Davis Cup captain Shamil Tarpischchev said: "Safin's injury is more serious than we first anticipated.

"It looks like he will be out of action for at least a month."

Mikhail Youzhny will instead lead the team in Ostrava next weekend alongside former world number one Yevgeny Kafelnikov, Nikolay Davydenko and 989th-ranked Igor Andreyev.

Also out with a wrist injury is USA's Andy Roddick, who will miss their tie against Croatia.

When Andy comes back , we will be stronger US Davis Cup captain Patrick McEnroe

The Australian Open semi-finalist has severe tendonitis after landing on his right wrist during his quarter-final victory over Younes El Aynaoui.

Neither Australian Open winner Andre Agassi nor US Open champion Pete Sampras are available for selection.

At 23, James Blake will be the most senior member of the team, with Taylor Dent, Mardy Fish and Robby Ginepri completing the line-up.

"This is an opportunity for our guys to step up, and it will make us a better team down the road," said US team captain Patrick McEnroe.

Former Wimbledon champion Goran Ivanisevic has been named in Croatia's team alongside Ivan Ljubicic, Lovro Zovko and Mario Ancic, but is likely only to play in the doubles.