World number two Maria Sharapova will not make her Fed Cup debut for Russia later this month because of shoulder and hamstring injuries.
Sharapova moved from Russia to Florida at the age of nine
The 19-year-old had been set to represent Russia for the first time in the first-round tie against Spain on 21-22 April in Moscow.
"I am especially bummed about the Fed Cup," Sharapova told her website.
"I was looking forward to playing in Moscow and representing my country in a team environment for the first time."
Sharapova, who has also been forced to withdraw from next week's Family Circle Cup in Charleston, moved to the USA aged nine and has never played for Russia.
"I will be speaking with the Russian Federation soon about future matches," she said.
Sharapova added: "My doctors are confident that, with five or six weeks of rest, I will be ready for the next events."