Today was a day to forget for the Williams sisters as they both crashed out of the French Open at the second round stage.

Serena fell to 20-year-old Spaniard Garbine Muguruza, while Venus lost to Anna Schmiedlova of Slovakia.

Both sisters are now into their 30s and the fact that they are coming towards the twilight of their careers age-wise is not going unnoticed.

We were joined by ESPN tennis analyst Luke Jensen who believes older sibling Venus is the one who falls under that label.

"Venus is suffering from this disease that she has been dealing with for the last couple of years. Her best tennis is far behind her," said Jensen.

While he admits Serena did not turn up today, he reckons her time at the top is not necessarily over.

"Serena is still the best tennis player, the best athlete on the WTA Tour. Earlier this year at the Australian Open she lost to Ivanovic. Ivanovic came out with an interesting gameplan and it should be the gameplan for any major underdog against Serena which is to try and overpower and take as many big chances as Serena and push Serena off of her toes and onto her heels. It worked in Australia and today was kind of the same thing." 

Jensen believes the Williams sisters' opponents no longer fear their aura after years of domination. But he also warned that Serena will be extra-motivated and will adjust her training plan, especially for her best surface which is at Wimbledon. 

Indeed he believes she has five good years and two Majors in her.