Slovakian Martin Klizan won his sixth ATP Tour title with a straight-sets victory over fellow qualifier Denis Istomin at the Generali Open.
The Rogers Cup will take place without Serena Williams, who has withdrawn due to personal reasons.
Fabio Fognini stands in the way of Juan Martin del Potro and a third title of 2018 after both men reached the final of the Los Cabos Open.
Venus Williams was unable to progress in the Silicon Valley Classic after an error-strewn display against Maria Sakkari.
Kei Nishikori won the first set but lost to Alexander Zverev in the latter stages of the Citi Open for the second year running on Friday.
After beating Marius Copil in the early hours of Friday morning, Andy Murray has withdrawn from both the Citi Open and the Rogers Cup.
Denis Istomin will take on Martin Klizan in the Generali Open final after they overcame Nicolas Jarry and Jaume Munar respectively.
With Andy Murray playing into the early hours of Friday morning, he is considering pulling out of his last-eight match at the Citi Open.
Former world number one Andy Murray is through to the last eight at the Citi Open after a third straight three-set victory.
Andy Murray bounced back from dropping the first set against Marius Copil to reach the last eight of the ATP's Citi Open on Thursday.