Andre Agassi has only just started to coach Novak Djokovic, but Goran Ivanisevic said: "I don't think it's going to last."
Though he needed treatment in his fourth-round match at Roland Garros, Stan Wawrinka is not concerned by his back problem.
Simona Halep enhanced her status as favourite for the French Open, while Caroline Garcia prevailed in her grudge match with Alize Cornet.
Caroline Garcia awaits Karolina Pliskova in the French Open quarter-finals after the second seed battled back to beat Veronica Cepede Royg.
Gael Monfils showcased more of his trademark agility on day nine at Roland Garros, while Petra Martic has an alcoholic tipple in her sights.
Should they meet at Roland Garros, Novak Djokovic is capable of halting the clay renaissance of Rafael Nadal, according to Andre Agassi.
After battling hard to take the first two sets, Stan Wawrinka cruised through the third to beat Gael Monfils in the French Open fourth round
A change in outlook is proving beneficial to Simona Halep, who reached the French Open quarter-finals with a win over Carla Suarez Navarro.
Williams is not only making plans for having a baby, she is already thinking about improving on her record of 23 major titles.
Djokovic's passionate desire to improve made it easy for Agassi to commit to working with him, the American told Omnisport.