This week the U.S. women's national team takes on Germany, France and England in the SheBelieves Cup, a yearly tournament that includes four of the world's best teams. After the men's abject failure to qualify for the World Cup, the women are on guard against a failure of their own. This tournament will be key in establishing the team that will go into World Cup qualifying this fall. The U.S. is still the top-ranked team in the world, but head coach Jill Ellis still has some question marks to address, especially on defense.

In 2015, the team's defense was the bedrock of the all-conquering World Cup performance. The U.S. allowed just one goal in the group stage, then swept through the knockout round without allowing a goal until leading 4-0 in the finals. Goalkeeper Hope Solo and center backs Becky Sauerbrunn and Julie Ertz (then Julie Johnston) were the key to letting the offense roam free.

In the two years since, Solo retired and Ertz moved up to a role in the center of midfield. Last year in the SheBelieves Cup, Ellis' solution to this change was to play with three central defenders at the back. That experiment ended when France smashed the U.S. 3-0 for its worst loss in a decade.

The team has switched back to a traditional back four, and is trying to figure out who fits where. That task will be more complicated in this tournament, as Sauerbrunn is out with a foot injury.

The key may be in goal, where Chicago Red Stars keeper Alyssa Naeher has been first choice to try to fill Solo's legendary gloves. Naeher has started all but a few games, but has not excelled. Veteran Ashlyn Harris has started the games that Naeher hasn't. Ellis may choose to rotate the two in the hopes of creating strength in depth.

North Carolina Courage center back Abby Dahlkemper has emerged as Sauerbrunn's new central-defense partner. But the pair has been uneven at best — and Sauerbrunn's absence will rob the two of a chance to build a rapport on the big stage.

At fullback, the U.S. has more options, with such veterans as Megan Klingenberg and Kelley O'Hara still in the running. Dahlkemper's North Carolina teammate Taylor Smith and Chicago's Casey Short were regular choices throughout 2017. Ellis will be using these high-pressure games to try to find four players who work well together.

This tournament will be a test of the United States' ability to control the tempo and flow of the game, which starts by being solid on defense. Not every team in the world is talented enough to press the United States and hit on the counter-attack, but all three of their opponents in this tournament can do so. It led to the Americans finishing last in the four-team tournament last year. This year's edition, which begins Thursday with the United States playing Germany, is a chance to improve.

Short takes

• The USWNT's offense, unlike the current defense, is in good shape. Striker Alex Morgan has been on fire for the U.S., scoring in eight of her past nine games, and such reliable stalwarts as Megan Rapinoe and Christen Press have been supplemented by newer arrivals in Lynn Williams and Mallory Pugh. The main question is whether the defense can support the high-powered attack.

• MLS was hoping for a good start to its CONCACAF Champions League campaign, but the first leg of the two-legged Round of 16 knockout matches wasn't kind to American clubs. Toronto defeated Colorado as expected, but Dallas lost 1-0 to Tauro FC (Panama), Seattle was upset by Santa Tecla (El Salvador) 2-1, and New York drew 1-1 with Olimpia (Honduras). The league's hopes of competing with Liga MX, which won three of its matches and drew one, are looking a little dim this week.

• A Spanish police officer died this week before an Athletic Bilbao-Spartak Moscow game after he had a heart attack while Bilbao and Moscow fans fought outside the stadium. With the World Cup in Russia this summer, it's natural to wonder whether Russian fans — who caused major trouble at Euro 2016 — can be held in check at soccer's showpiece.

WEEKEND WATCH GUIDE

Liga MX: Tijuana at Club América, 9 p.m. Saturday, Univision. Midway through the spring season, América is undefeated and atop the league, a place it has only rarely found itself in the past couple of years. Tijuana, one of the most successful regular-season teams in that time, is hoping to inflict América's first loss of the campaign.

Premier League: Chelsea at Manchester United, 8 a.m. Sunday, NBCSN. Manchester United manager Jose Mourinho insults everyone, but his war of words with Chelsea manager Antonio Conte has gone beyond the usual. Both squads are fighting to stay in the Champions League places, with no room for error for either side.

English League Cup Final: Arsenal vs. Manchester City, 10:30 a.m. Sunday, ESPN. Manchester City's shot at winning everything ended earlier in the week, as the powerhouse Citizens lost to third-division Wigan in the FA Cup. That said, Arsenal — having its worst season in years — is all that stands between City and its first trophy of 2018.

Ligue 1: Marseille at Paris Saint-Germain, 2 p.m. Sunday, beIN. This match is known as "Le Classique," the biggest rivalry in France. It's capital vs. province, north vs. south, traditional powerhouse Marseille against nouveau riche PSG. Nobody's catching PSG in the title race, but Marseille would dearly love to claim a rivalry victory.

Writer Jon Marthaler gives you a recap of recent events and previews the week ahead. • jmarthaler@gmail.com