KANSAS CITY, Kan. — Sporting Kansas City has a chance to pull off one of the biggest upsets in MLS history on Sunday.

After a shocking 4-1 win in Game 1 of the MLS Cup Playoffs as an 8 seed over 1 seed St. Louis City SC on the road, Sporting will host Game 2 with the potential to advance to the Western Semifinals with a win.

A loss will send the series to Game 3 next Sunday in St. Louis.

The MLS playoff structure is rare in the soccer realm with very few leagues playing a best of anything series.

Head coach Peter Vermes said the biggest challenge is that both teams probably won’t switch much of their game plan throughout the series.

“I think what it comes down to is maintaining your effort in the game,” Vermes said Friday.

“There’s so much physicality to it in that your conditioning and for 90 minutes and all that stuff, that plays a big part in it. I really think it’s more about you trying to get rested, prepared, recharge and then you’re ready to perform again.”

St. Louis has beaten Sporting twice at home in the regular season with Sporting winning twice as well including the playoff win in the inaugural year of this rivalry.

Teams that know each other very well and respect each other are fighting for their season on Sunday.

“I don’t know what they’re gonna throw out there but it’s not gonna be an easy game for us,” midfielder Roger Espinoza said.

“Intensity always gotta be there from our team. You know it’s gonna be there from both teams. It’s the playoffs. We just gotta be very smart like we were over there.

“Any little mistake, it can be hurtful for us.”

“In the last game, we were very opportunistic,” Vermes said.

“Your habits are already kind of ingrained in you. It’s whether or not you can implement some of the nuances that you may put into the game.

“Now it’s this next game that we’re focused on. And we have to get back to thinking about what we prepared for and then getting ready to execute when the weekend comes.”

SKC hosts STL on Sunday at 4 p.m.