The Aussie believes that Elias Ymer wasn't owning up to a double bounce, but it never was called.
Canadian trio join Simona Halep as wild-card recipients.
Newport finalist Jenson Brooksby topped No. 53 Frances Tiafoe 7-6(4), 7-5 in Washington, DC for the biggest win of his career.
"I'm dealing with problems like we all are. I feel like it affected me a little bit today," said Nick Kyrgios after opening-exit in Washington, DC.
Felix Auger-Aliassime lost his Olympic opener, but learned from the experience.
A trio of big stars will sit out next week's Omnium Banque Nationale in Montreal.
The two-time champion and the rising American will joined the star-studded draw in the last event prior to the US Open.