Mouratoglou, a long-time coach of Serena Williams, will work with two-time Grand Slam champion and former world number one Simona Halep full-time, the Frenchman said on Thursday. Mouratoglou has not been coaching for nearly a year as Williams has not played on the tour since she injured her leg at Wimbledon last year and there is no clarity on the 40-year-old's return to action. "In the last eight months, I realized how much I missed coaching. It is the passion of my life, and I still feel like I have so much to give," Mouratoglou said in a statement.