Mauro Biello urged his Canada Under-23 men’s national team to pick up their slingshot and take down heavily favored Mexico in Sunday’s Concacaf Olympic qualifying semifinal in Guadalajara (9 pm ET | Fox Sports, TUDN in US, OneSoccer in Canada).

That upset would send them to the Olympics for the first time in 37 years and rank as “probably one of the biggest achievements in Canadian soccer history” as well as “a David-and-Goliath story,” in Biello’s words.

“We’re well aware of who the opponent is, it’s the giant in Concacaf,” said the former CF Montreal head coach in a Saturday press conference. “We’re in a position where we wanted to be, in terms of now getting to that one game that allows us to go through to the Olympics, and we’re looking at it as that: It’s a one game, anything can happen.

“We’re preparing to play the giant and for us it’s all about now reducing those spaces, denying those spaces for them to operate in and being very specific of how we attack them and how we put them under pressure in different moments. Obviously Canada has never won in Mexico, but at the same time it’s a tremendous opportunity for us to make this happen.”

Biello faces several lineup decisions but probably the biggest question is the fitness of Derek Cornelius, the commanding center back and team leader who’s been pivotal for Les Rouges. The Vancouver Whitecaps standout scored Canada’s goal in their group-stage finale vs. Honduras but later limped off with a knee or lower-leg injury that raised doubts about his status for Sunday.

“He got treatment yesterday so it’s progressing every day,” said Biello of his defensive talisman. “We feel at this point, from the medical team, they’re very confident that he’ll be available.”

Few outside of the Canada camp are giving them much of a chance, given Mexico’s history of dominance a) on home soil, b) in Olympic qualification and c) head-to-head vs. Les Rouges. But they’re embracing the long odds, with an eye towards the glory it could reap them should they navigate past what has thus far been the best team in this tournament by some margin.

“We’re playing against host nation, the favorites. But that just gives us a little bit more motivation to take down the host in their country, right?” said U-23s and Montreal goalkeeper James Pantemis, who confirmed that he and his teammates have been practicing penalty kicks in preparation for the possibility that this clash will have to be decided in a shootout.

“We’ll be going into that game, obviously, knowing we’re the underdogs but we’re going to feed off that. And I think it would be a fantastic story not only to qualify for the Olympics, but to take down the hosts. So that’s what we’ll be looking to do.”

Biello had plenty of praise for Mexico’s sharp pressing and dangerous attack, spearheaded by Alexis Vega and former LA Galaxy winger Uriel Antuna and fueled by the late-arriving runs of Carlos Rodriguez and Sebastian Cordova, this event’s leading scorer with four goals so far.

“Cordova and Rodriguez, two very good players that really play well between the lines and really operate their movements coming into the box late. These are all things that we need to mitigate and be aware of, and then the forwards such as [JJ] Macias or Vega – Vega also is a very good player, technical player that finds spaces, he can shoot from distance,” said Biello.

“I think the mindset for us was always to stay compact and tight and not give space to the opponent and really be aggressive when we can be vs. these players. I think if we do that well, we could slow the machine down and grow – and it’s about growing in this game and then believing we could get something out of it.”

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