But if wins over Mannarino, Nadal and Juan Martin del Potro have been any indication, Shapovalov-who is the youngest player ever to reach a Masters 1000 semifinal-could be on a collision course for a championship clash with Federer.
Still there was an impressive element of never-say-die in Shapovalov's game.
But my game plan worked better against Bautista-Agut than against Ferrer.
It was an even contest in the first set, Shapovalov and Zverev going toe-to-toe until the ninth game.
It was not enough for the underdog, though, and Haase was beaten when a loose forehand drifted wide on Federer's first match point.
This was when the intestinal fortitude of Zverev shone brightest.
Zverev was as cold as ice from that point, though Shapovalov battled, claiming the decisive break for a 6-5 lead to silence the partisan stadium.
Shapovalov double-faulted as he crumbled for the first time, handing Zverev a 5-4 lead, and the German served out the set.
Germany's top player echoed those sentiments in press, elaborating on what he felt could be the beginning of a solid rivalry. "A bit surprising, to be quite honest, because I hadn't practiced much".
"I know I can't become number one here, I'm just playing Montreal for the tournament that it is, and I'm trying to win it for the first time in my career", Federer said. I was insecure. I had a lot of problems with other injuries after. "David can play a lot better, too", Federer said.
The junior Wimbledon victor and tournament wild card entered the week with three ATP-level wins and has added four more so far.
With top seed Rafael Nadal knocked out in the third round by Canadian teenager Denis Shapovalov, 19-time grand slam victor Federer is thick in the fight for a return to the top of the ATP list. All the while Shapovalov won the adoration of the local fans and dealt with the newfound fame and pressure that goes with it quite admirably. Will he be able to consistently reproduce the inspired tennis when the fatigue of the tour sets in?
Federer posted his seventh consecutive win over the Spaniard and improved his season record to 34-2.
Federer said he knows Haase well from serving with him on the ATP player council and from practising together.
"It's a big bonus right now and I hope I can play as free as I have so far in the finals tomorrow". I won four. The one that I lost was against Roger.