'Tough' Serena Williams says she could play until 40

'Tough' Serena Williams says she could play until 40Johannesburg, Oct 22 - American tennis player Serena Williams has not ruled out being able to play until 40 years old and admitted that ten years ago she would never have expected to be still playing now.

According to Sport24, speaking ahead of the WTA Championships in Istanbul, Williams refused to rule out the improbable because she has already achieved what seemed to her impossible anyway.

Serena said that at one point she thought she would never play again and just wanted to survive, adding that it put a lot of character in her and even more mental toughness.

Williams is firm favourite to retain the WTA Championships title and win it for a fourth time, the report said.

However, her nearest rival, Victoria Azarenka, the Belarussian , has beaten her twice this year and ran her close in the US Open final last month, the report added. (ANI)