Former Australian Open champion Stanislas Wawrinka will play at the Paribas Tennis Classic at The Hurlingham Club next month.
The world number nine will play at the four-day event along with the likes of Gael Monfils and youngster Borna Coric, who has recently beaten both Andy Murray and Rafael Nadal.
"I'm really pleased to be playing in the BNP Paribas Tennis Classic again because it gives us players the crucial final opportunity to practice before Wimbledon," said 30-year-old Wawrinka.
Kei Nishikori, Tomas Berdych, Marin Cilic and Grigor Dimitrov have all previously confirmed that they will feature at the event, which gets underway on Tuesday, June 23.