Petra Kvitova is on track to play at Wimbledon less than seven months after she was attacked by an intruder.
Maria Sharapova is to enter Wimbledon qualifying as she continues her comeback from a 15-month ban for doping.
Maria Sharapova has been denied a wildcard invitation for the French Open, which begins later this month.
Roger Federer will miss the French Open and the rest of the clay-court season.
Novak Djokovic has parted company with his entire coaching staff.