Sampras has not played for seven months

Sampras, who has not played a tournament since winning the US Open last September, has pulled out of all five events he had entered this year.

Last week, the seven-times Wimbledon champion asked for a wild card into the Queen's Club grass court tournament.

However, his brother Gus said the Queen's request was not a solid indication that he will come back.

Sampras requests Queen's spot

"It's just standard business," he said. "He hasn't made up his mind whether he'll return."

US Davis Cup captain Patrick McEnroe said he spoke with Sampras in March and believes he will play Wimbledon.

"But he doesn't know - nobody knows," McEnroe said. "He seems perfectly happy doing what he's doing right now."

McEnroe added that if Sampras returns he would have a good chance of winning his eighth Wimbledon title.

"After what I saw at Flushing Meadows last year, nothing will surprise me," said McEnroe.

"He can show up at Queen's and win two matches and then lose, play one exhibition, and if he wins two rounds at Wimbledon, everyone in the locker room is going to be shaking in their boots."