Two hours later, Monfils had his answer and he pulled out after talking to his coach, Liam Smith. He explained, "I'm playing very well right now". That quarterfinal was postponed until Saturday because of inclement weather with Monfils leading 30-0 in the first game of the first set.
"I've played a lot of these".
The rain delays had a domino effect on Saturday's schedule.
Nadal will face eighth-seeded Daniil Medvedev, a 6-1, 7-6 (6) victor over sixth-seeded Karen Khachanov, in the all-Russian first semifinal.
Medvedev, World No. 8, had no trouble with Khachanov in the first set, cruising in just 23 minutes.
Looking to watch (and bet) on the Daniil Medvedev v Karen Khachanov live streaming online? "Before the match, I hadn't thought about that, but I quickly understood it was going to be the match for me to become the top one in Russian Federation, maybe top eight in the world". "We know each other pretty well".
It was Medvedev's first win over Thiem in three career matches. "Yeah, of course, it's extra special", he said.
The Russian also suggested that there always is some extra pressure to play against the Big Three. It's different, I have to say.
"As a kid, I saw them already winning Grand Slams on TV", Medvedev added.
"This is just not enough in the quarter-finals of a Masters 1000, especially against a guy like Daniil, who is in great shape, who is playing awesome tennis".
"I won't be intimidated".
"With all the travelling and short transition, two very tough matches yesterday (Thursday) and two days ago, I think the battery was empty today. Hopefully, I can do it tomorrow", the 33-year-old concluded.
Tennis Canada will reimburse ticket-holders for the cancelled session.
Nadal won the event for the third time in Montreal.
Up next for Andreescu will be unseeded American Sofia Kenin, who extended her impressive Toronto run with a 7-6 (7-2), 6-4 win over Ukrainian former champion Elina Svitolina.
Spain's Marcel Granollers and Argentina's Horacio Zeballos, playing together for the first time, defeated Robin Haase and Wesley Koolhof of the Netherlands 7-5, 7-5 to win the men's doubles final at the Rogers Cup. It was rescheduled for 1 p.m. Saturday afternoon.