"You're going to expect hell," said the veteran of three World Cup qualifiers.
"This is their lives, this is all they have for them," he added of the soccer-crazy Hondurans. "This is what we have to make it for ourselves too ... It's come down to the stage where it's become the most important game not just for ourselves but the entire country (of Canada)."
De Guzman and the Canadian team will emerge Tuesday afternoon out of a battered tunnel that looks like something out of "Mad Max Beyond Thunderdome."
A yellow metal mesh door topped with poles bars entry when the tunnel is not in use. Barbed wire at the top is there to dissuade fans from trying to climb the fence or moat that surrounds the pitch and its neighbouring track. But penned in the stands, those around the tunnel will bang the metal roof and walls to create an unholy din as the visitors walk below.
Two teams will enter Tuesday. Likely only one will leave to continue its World Cup qualifying campaign.
Canada (3-1-1) just needs a tie or win to advance to the final round of qualifying in CONCACAF, which covers North and Central America and the Caribbean.
The Hondurans (2-1-2) have to win.
Panama (3-1-1) plays in Cuba (0-5-0) at the same time. A shock upset win by Cuba could mean that Canada could still lose and advance, depending on goal difference. More likely Panama and either Canada or Honduras will move on.
Coach Stephen Hart calls Tuesday's match "massive."
"The biggest game of my career," said Canadian captain Kevin McKenna, who said he got goosebumps just talking about it.
"This decides a lot of things," said de Guzman. "For myself, my future, the future of football in Canada."
It speaks volumes about Canadian men's soccer that a game of such proportions is just for a chance to play in another round of World Cup qualifying. Ten more matches await if Canada succeeds Tuesday.
The last time Canada made the final round was in 1997 when it finished last in the six-team group with a 1-6-3 record. And Canada's record of participation at the World Cup has been stuck at one for 26 years.
Hondurs has made the World Cup twice — in 1982 and 2010.
Mexico has already qualified for the final round of CONCACAF qualifying and will be joined by five others.
Three teams will emerge from the so-called "hex" qualifying round to represent CONCACAF at the 2014 World Cup in Brazil. The fourth-place team will challenge the Oceania winner in a playoff to determine who joins them in the final field.
On Monday, a national holiday in Honduras, workers put together the advertising hoardings around the pitch and looked to dress up the crumbling stadium. Music blared as the Canadians worked out — in preparation for the lengthy tailgate party that will surround the game.
Built in 1997, the stadium looks like it hasn't been touched since. Today it is almost a post-apocalyptic vision. One look at the Caballeros or men's washroom is a sphincter-tightening experience likely to trigger an immediate exit.
Tuesday, the sun-drenched venue could be full of as many as 40,000 screaming Hondurans and a handful of hardy Canadians.
Savage heat, a hostile crowd and a cage-like arena sound like a recipe for severe stress. But Hart wants his players to savour the moment.
He had two messages for his team.
"One, we've very seldom been in this position so enjoy it," he said. "And two, it's like a final."
"I want players to enjoy the moment," he added. "They can play the game, they have the ability. It's to bring it out in a relaxed, concentrated form."
Hart, a native of Trinidad who is no stranger to heat, did admit he hopes for some more cloud Tuesday. The 30-degree-plus heat was tolerable when cloud concealed the sun. It was brutal when the sun had the sky to itself.
"It'll be tough," said Hart. "The environment's going to be the biggest challenge."
"It's hot but we've got to deal with it," added McKenna. "They've got to deal with it too."
Honduran media reported Monday that the mood in the home camp was "kill or die."
"That's their culture. They've declared a national holiday, that alone tells you how important it is," said Hart, refereeing to the fact that the Discovery of Americas or Columbus Day national holiday has been extended through Tuesday.
The violent motto is perhaps fitting in a country that tops the global per capita murder rate. San Pedro Sula itself was named the world's most violent place in 2011 by Mexico's non-profit Civic Council on Public Security and Criminal Justice.
On the weekend, at least 11 people were murdered in three violent incidents in the eastern part of the country. One incident saw eight young men chatting outside a soccer field when they were gunned down by gunmen riding in a vehicle.
Guns are everywhere, from shotgun-wielding security guards to police with automatic weapons. Honduran law allows citizens to have permits for five firearms.
While the locals are friendly, they are quick to notice foreigners. It doesn't take much to stand out here.
The Canadians are living in a protective bubble during their short visit here, however. They are staying in a luxury hotel with security and their only planned forays outside the hotel are for Monday's training and Tuesday's game. They will leave the stadium under police escort and charter out of the country as soon as possible after the game.
And unlike Panama, the Canadians have not been disturbed by overnight street demonstrations.
But the Canadians cannot have missed the bleak views down the side streets off the main road that takes them to the stadium. It is a dark, disturbing vista.
Hart's team will be missing strikers Dwayne De Rosario (knee) and Olivier Occean (suspension), forcing him to rejig what has been a hit-and-miss offence. Canada's defence has been steady, however.
For de Guzman, Tuesday's game is just the latest test of character.
"We've been a tough unit mentally, physically and it's about time we show this on the road — how complete of a team we are."
NOTES — Canada is ranked 61st in the world by FIFA, good enough for sixth in CONCACAF. Honduras is No. 66 (seventh in CONCACAF) ... The two teams tied 0-0 in Toronto earlier in the round, the only home points dropped by Canada.