Belinda Bencic will take on Liudmila Samsonova for WTA glory in Berlin after they won their respective semi-finals.
Matteo Berrettini maintained his impressive week at Queen's club, while Andrey Rublev continues to perform well ahead of Wimbledon.
World number three Simona Halep says she is not ready for tournament tennis as she builds up her fitness with Wimbledon fast approaching.
After her quarter-final win in Berlin, Belinda Bencic said she plays better when she is mad.
Matteo Berrettini fended off Dan Evans 7-6 (7-5) 6-3 at Queen's Club, while Andrey Rublev beat Philipp Kohlschreiber in Halle.
Grand slam winner Dominic Thiem cited a run of poor form as he announced he would not compete for Austria at this year's Olympics in Tokyo.
After she withdrew from the French Open last month, Naomi Osaka will not feature at Wimbledon but will be back for the Tokyo Olympics.
Andy Murray gave a frank assessment of his performance in a loss to Matteo Berrettini and says he is still troubled by a groin injury.
Karolina Pliskova will be sick of the sight of Jessica Pegula after losing to her for the fourth time this season, this time in Berlin.
The 2020 US Open was played without fans, but the USTA is planning for packed stands at Flushing Meadows in August and September this time.