Serena Williams joins growing list of tennis stars to skip Tokyo Olympics

• US player declines to expand on reasoning for not going
• Nadal, Thiem already have said they will not be playing

Serena Williams will not be travelling to Tokyo for the Olympic Games, the 23-times grand slam singles tennis champion said on Sunday, albeit without giving the reasons behind her decision.

Williams, who will turn 40 in September, won the singles title at the London Olympics in 2012 and she has also picked up three gold medals in doubles with sister Venus - in Sydney (2000), Beijing (2008) and London.