The Mutua Madrid Open revealed the names of the first four invitees to the WTA and ATP main draws: Simona Halep, Caroline Wozniacki, Kei Nishikori and Martín Landaluce.
Former world number four Kei Nishikori won his first ATP Tour match in 19 months at the Atlanta Open on Tuesday.
Forgotten ATP stars Milos Raonic and Kei Nishikori are back from injury and made winning starts in their respective returns this week.