Top-10 duo Kei Nishikori and Tomas Berdych will both feature at the BNP Paribas Tennis Classic at the Hurlingham Club this summer.
The exhibition event, which features some of today's top players and some legends of the past, runs June 23-26, just before Wimbledon begins on June 29.
"The Hurlingham is without a doubt the best place to warm-up before Wimbledon," said Nishikori. "I'm delighted to be returning this summer so that I can get those vital last matches in before Wimbledon."
Previous players to appear at Hurlingham include Andy Murray, Rafael Nadal and Grigor Dimitrov.
