That could be a huge problem for manager John Herdman because Davies has become such a useful asset for his side not just because of his top level quality, but due to him being so versatile.
A left-back at club level, Davies usually plays either left-wing or as a number 10 for Canada depending on whether they play 4-4-2 or with three-at-the-back, so his absence could force him to change his tactics here.
If Davies is out, it should guarantee starts for both Cyle Larin and Jonathan David as a striking duo.
Larin is Canada's record goalscorer while David has more goal contributions than caps for his country, so both represent a big threat for Canada.
Atiba Hutchinson is set to win his 99th cap for Canada and will become one of the oldest World Cup players of all time at 39 years of age.
It is almost 20 years since the Besiktas man made his international debut and he will now finally get the chance to play at a major tournament, and he will do so as captain.
Herdman may want to use a three-at-the-back to match up with Belgium's system, so that could see another versatile individual, Alistair Johnson, utilised as a centre-back as opposed to his usual right-back position.
Backup goalkeeper Maxime Crepeau broke his leg in the MLS Cup final recently so heartbreakingly will miss the entire tournament, while the much-travelled Red Star Belgrade man Milan Borjan will start between the sticks.
This is a fairly inexperienced national side as 22-year-old duo Davies and David are among the highest capped players in the squad.
Canada possible starting lineup:
Borjan; Laryea, Johnston, Steven Vitoria, K Miller, Adekugbe; Buchanan, Hutchinson, Eustaquio; David, Larin