Coach says Williams is enduring 'difficult period' in her life

World number one Serena Williams' French coach has said that the American tennis ace is enduring a difficult period in her life.

Williams, whose Wimbledon campaign ended with her in tears on the verge of fainting, was knocked out in the third round of the singles at the All England Club before she retired from her doubles where her sister Venus led her off the court with problems attributed to a 'viral illness'.

Williams' coach Patrick Mouratoglou admitted that the 32-year-old was facing a series of challenges in a season where she has yet to get beyond the fourth round at any of the Grand Slams, despite the coach refusing to discuss the American's current mood, Sport24 reported.

Mouratoglou said that Williams is clearly going through a difficult period, but added that since Wimbledon, they have had long hours of talks and are getting back to work.

The Frenchman said that she is currently in the mood to get back to training so she can return even stronger, adding that at no time was there any question of them stopping their collaboration.