Sharapova has yet to represent Russia despite being born in Siberia

Sharapova, who is nursing an injured shoulder, has never played Fed Cup for Russia but cheered from the sidelines.

But world number two Svetlana Kuznetsova said: "She said she wanted to be our practise partner but if you can't play how then can you practise?"

Players cannot play at the Olympics if they are not available for Fed Cup.

The Russian team wrapped up their third Fed Cup win in four years on Saturday, but questions about Sharapova's presence were in danger of overshadowing the team's achievements.

When asked about Sharapova's role as a supporter, Kuznetsova replied: "Oh please, don't ask me that question again. I had enough already."

Sharapova, 20, was born in Siberia but moved to America as a youngster where she was coached in Florida at the Nick Bollettieri Tennis Academy.

She is still based there and although she was due to make her debut for Russia this year, a last-minute pull-out from the Fed Cup semi-final lead to her being dropped.

"If you haven't played Fed Cup all year, it wouldn't be fair to just show up for the final," world number five Anna Chakvetadze said.

"It's not fair to all the other girls who committed themselves to the team's cause."

While Sharapova must still convince her team-mates, she did score important points with the International Tennis Federation (ITF).

"Her presence in Moscow certainly didn't hurt," an ITF official told Reuters on Sunday.

"She was injured and couldn't play, but by being here she clearly demonstrated her commitment to the Fed Cup and that will certainly enhance her chances (of playing at next year's Olympics). It's a big plus for her."