Over the last few years, the Union have proven themselves against pretty much every opponent that’s been a measuring stick for the team’s success.

But there’s still a short list of teams the Union haven’t overcome yet, and one of them will be at Subaru Park on Sunday.

It’s been six years since the Union’s only win against the Portland Timbers in 11 all-time games. Portland has won all five meetings since then, including 3-1 victories in Chester in 2017 and 2019.

For a Union team that entered the weekend in third place in the Eastern Conference, snapping that skid would be a fine way to enter Major League Soccer’s June break. After Sunday’s nationally televised game (7 p.m., FS1, Fox Deportes), the league will go dark for a few weeks as its players head off to the Concacaf Nations League, European Championship, and Copa América. The Union won’t play again until June 20.

The squads we’ll see this weekend are considerably different from their predecessors, including those that met last year in Major League Soccer’s summer tournament in Orlando — a 2-1 Portland win in the semifinals. But it probably isn’t a coincidence that in every game of the Timbers’ winning streak, superstar playmaker Diego Valeri has had a goal or an assist.

» READ MORE: Dániel Gazdag shows hints of his potential in Union debut

Now 35, the Argentina native knows his time in the center of the action is starting to tick down. But right now, he’s as important as ever, because Portland has almost a full team’s worth of players out injured. Among them are starting goalkeeper Jeff Attinella, centerback Larrys Mabiala, crucial midfielders Diego Chará and Sebastián Blanco, winger Andy Polo, and striker Jaroslaw Niezgoda.

“It starts with Valeri, trying to limit his touches,” Union manager Jim Curtin said. “He’s going to get on the ball because he’s so special and talented. But you want to try to make him play square and backwards as much as possible.”

You’ll also see one of the most talked-about young Americans in MLS this season, central midfielder Eryk Williamson. Fueled by being spurned from the U.S. men’s Olympic qualifying team — and by watching the team flame out — the 23-year-old has had a terrific season. On Sunday, he’ll match up with a player who’s shown a similar mix of offensive and defensive skills in his career: Union captain Alejandro Bedoya.

“Williamson, for me, is one of the top midfielders in our league,” Curtin said. “Maybe doesn’t get the accolades that some others [do], but he’s had a great season.”

As the Union aim for their third straight shutout win, they will get a boost from Subaru Park being opened to 75% of its 18,500-seat capacity, ahead of a full reopening on June 23.

“In the empty stadiums, it is kind of a neutralizer, it levels the playing field a bit,” Curtin said. “But now when the fans are in there, and they get excited, and they get behind you, or when you’re on the road and they’re against you, it becomes that much more rewarding to get points.”

» READ MORE: Soccer on TV: How to watch this weekend’s UEFA Champions League final