After falling into a 2-0 deficit in Leg 1 at Estadio Azteca, it will take a near-flawless performance for Jim Curtin's group to advance past the storied Liga MX outfit.
Given that challenge, do the Union have a shot at pulling off an incredible comeback? The Extratime crew discussed as much on their latest episode, with the general consensus being that they hope to see Philadelphia play like a team with nothing to lose.
"I think Club America, they're currently atop the standings in Liga MX, they're playing just lockdown, strangle-you defensive soccer," co-host Matt Doyle said. "I think they are substantial favorites. It is going to be very hard to push the number of players forward you need in order to score two goals and not leave yourself exposed defensively.
"So they would need a little bit of magic on this night. Philly have found magic in the past. Jim Curtin's been one of the best managers in the league in the last five years, so it's not impossible. But this is a mountain. This is not a hill that you're walking up, this is trying to scale a mountain. If you're the Union you just have to go out there, grip and rip it. You have nothing to lose. Put on a show for your fans and go as hard as you possibly can for 90 minutes."
Co-host David Gass agreed, saying that if nothing else, the match is setting up to have some good entertainment value. Gass said he expects Philly to come out firing from the get-go, and if they actually manage to pull off a shocking comeback upset it'll just taste that much sweeter.
"I think this is going to be a team that's going to press out of the gate, out of control in Philly and try and upset Club America and try and change the tempo of this game and try and get an early goal, something to play off of and get the behind them," Gass said.
"And we know that building when Philly's good, that place jumps and especially on a weekday night under the lights. Philly's had some success over the last two years in that building in games like this. So if they're going to do it, they need a miracle, they need to jump all over this team early. It could be entertaining, at the very least, and if Philly wins, oh, that'll be glorious."
Curtin has already said in the lead-up that he hopes his players will empty their tanks to try and flip the result. They're also juggling the MLS stretch run, sitting fifth in the Eastern Conference standings as Audi MLS Cup Playoff spots become more precious.
All told, Doyle said pride is of paramount importance in this backs-against-the-wall situation.
"That's the thing, right? Go out there to win but put on an entertaining 90 minutes," Doyle said. "Soccer fans in America are savvy. They know what Club America is in this region. If you go out there and show no fear and go toe-to-toe with them and you lose 2-1 on the night, the fans will respect that. They'll be entertained by that.
"I'm not talking about just moral victories, I'm talking about creating the sort of bedrock of what you are as a team. And I think the Union have been really good about that under Jim Curtin and win or lose, they have a chance to do that in this game."
For more Extratime analysis after a jampacked Week 24, check out the entire episode here.