When the Portland Timbers headed to Sporting Kansas City for the second leg of MLS' Western Conference final series, Zarek Valentin knew his fifth-seeded team was the underdog.

And he knew that if the Timbers prevailed, they’d be an even bigger underdog playing the championship game against Atlanta United, in Atlanta, with an MLS Cup Final-record crowd of 72,000 raising the roof at Mercedes-Benz Stadium.

Valentin is a Lancaster native, and probably the biggest Eagles fan in all of MLS. So before he left for Kansas City, he gave himself some inspiration the best way he knew how:

He bought an underdog mask.

After Portland’s dramatic 3-2 win, Valentin put the mask on and posed for a picture with hundreds of Timbers fans who had traveled to the game.

“The more I started to see things pop up here and there about our team being underdogs ... it struck a chord inside of me," he said. "So I went on Amazon and threw in ‘dog mask,’ and it just so happened that the ‘Amazon Choice’ one was the actual one Lane Johnson wore. At least, that’s how they advertised it.”

Valentin’s charisma extends beyond both forms of football. He’s a good guy off the field, too.

Earlier this year, he put himself up for a bet that if one of his tweets got retweeted 10,000 times, he’d wear a ribbon in his hair in a game as a tribute to Portland Thorns colleague Hayley Raso. The tweet went viral and easily beat the 10,000 mark. Valentin duly took the field for a game in June with a green ribbon in his (admittedly long) hair.

But that wasn’t all. He used the gambit as a charity fundraiser, working with the Timbers supporters' club to sell rainbow ribbons in support of a local organization that fights discrimination against LGBTQ youth. They raised $8,000.

Entering Saturday’s game (8 p.m., Fox and UniMás, with pregame coverage before then), Atlanta is indeed favored, and not just because of home-field advantage. United were MLS' highest-scoring team in the regular season with 70 goals, of which 31 came from newly crowned MVP Josef Martínez. Dynamic playmaker Miguel Almirón had 12 goals and 14 assists.

Portland will have one advantage Atlanta won’t, though: an MLS Cup in its trophy cabinet. Atlanta is playing for its first title, and to end the city’s 23-year pro-sports championship drought. If United win Saturday, they’ll have claimed a trophy in their second season of existence, while the Hawks and Falcons still have none. The Braves' 1995 World Series is the city’s only major title.

The Timbers won it all in 2015, the year before Valentin came back from a three-year sojourn in Norway. Eight current Timbers players were on that team, which beat the Crew in Columbus in the final. Valentin has heard all the stories and wants to have the experience himself -- especially after living through the Eagles' triumph last winter as a fan.

“I was crying. My dad was crying. My brother was crying,” he said. “I remember so distinctly the feeling I had. The idea of potentially giving other people that is one of the best things you can achieve as an athlete.”

The Timbers aren’t often underdogs. In Diego Valeri, Diego Chará and Sebastián Blanco, Portland has three of MLS' best midfielders - especially Valeri, whose goals and assists have made him one of MLS' stars. Valeri and Blanco both scored in Kansas City, with Blanco smashing a 30-yard stunner.

Blanco also scored in the Timbers’ epic win over arch-rival Seattle in the Western Conference semifinal. Portland’s annual showdowns with the Sounders are some of the biggest games in MLS, drawing raucous crowds in both cities. Those experiences have given the Timbers ample practice at facing the kind of hostile environment that awaits in Atlanta.

“Guys on our team seem to really enjoy those moments," Valentin said. “It’s almost as if we’re playing with house money a little bit. ... We’ll embrace that role and continue to have the inner belief that we need, and hopefully can go in there and win a MLS Cup."