The biggest-ever FIFA World Cup is unfolding in MLS’s backyard, creating the potential for a massive summer transfer window.

With 48 countries participating, more than 1,000 players have had the chance to familiarize themselves with soccer in the United States.

A number of those players have been practicing at MLS team facilities, too, giving them an up-close view of truly world-class training centers. 

Conversely, MLS front offices have had a chance to watch games and scout for talent at this World Cup while their teams are on break.

So, which World Cup players could MLS teams target as summer signings? Let’s dive in before the market formally opens on July 13.

Gio Reyna

• Country: USA
• Club: Borussia Mönchengladbach (Germany)
• Position: Midfield

As talented a player as the United States has ever produced, the New York City FC academy product could be looking for a new home if reports are to be believed. 

Reyna, who scored one of the best goals of the World Cup in the USMNT's tournament opener against Paraguay, is a game-changer. 

Of course, the attacking midfielder comes with an injury risk: Reyna has rarely been fit for a full season during his professional career in the German Bundesliga. But when healthy? The 23-year-old is a major asset in the attack.

Potential destination: Austin FC, LAFC

Without a top-tier No. 10, Austin FC could use Reyna’s creativity if they can fit him into the squad from a roster rules standpoint. Elsewhere, LAFC may be in the market for a central playmaker should Venezuelan starlet David Martínez move abroad.

Luc de Fougerolles

• Country: Canada
• Club: Fulham FC (England)
• Position: Defender

This past season, de Fougerolles played nearly 2,000 minutes while on loan from Fulham in Belgium’s top flight. He's also emerged as a starter for Canada at the World Cup. Not a bad résumé for a 20-year-old center back, is it?

With good speed, strength and mobility, de Fougerolles would improve several backlines across MLS. While he’s not an elite passer, he’s a steady distributor and can drive the ball forward on the dribble. This young defender can also be overly aggressive in aerial battles and take too many risks with his positioning. Still, he’s got the tools to be a valuable addition in the summer window.

Potential destination: Columbus Crew, Orlando City

Both Columbus and Orlando need at least one starting-caliber center back, with the Crew potentially reverting to a back three under interim coach Laurent Courtois and the Lions in need of help next to Robin Jansson.

Elijah Just

• Country: New Zealand
• Club: Motherwell (Scotland)
• Position: Winger

One of this tournament’s breakout stars, Just’s brace in New Zealand’s opener against Iran was a defining moment for the All Whites. Playing as a left winger, he showed off clever combination play, vision and, of course, goal threat.

The Motherwell attacker is coming off a strong season in the Scottish Premiership, too, having notched seven goals and eight assists in league play.

A move – to MLS or elsewhere – seems inevitable for Just.

Potential destination: D.C. United, St. Louis CITY SC

We’ve already seen St. Louis dip into the Scottish top-flight for players (see: Dante Polvara) under their new sporting regime. Would it be a shock to see them add to the attack from that same league? D.C. United, for their part, could use more talent in the half-spaces to pair with DP strikers Tai Baribo and Louis Munteanu.

Patrick Berg

• Country: Norway
• Club: Bodø/Glimt (Norway)
• Position: Defensive midfielder

Perhaps the most widely known player on this list outside of Reyna, Berg would likely be a Designated Player because of the fee Norwegian club Bodø/Glimt would demand for his services.

After a tremendous UEFA Champions League campaign this past season and now with World Cup appearances for his country, the 28-year-old would fetch a pretty penny.

Berg is smooth on the ball, can conduct play from the defensive midfield spot, and would immediately be one of the best No. 6s in the league.

Potential destination: Real Salt Lake, Toronto FC

The biggest need for Real Salt Lake may be in their double pivot, and they have a DP spot to play with. Toronto also have a DP spot available and are in the process of overhauling their spine.

Emam Ashour

• Country: Egypt
• Club: Al Ahly (Egypt)
• Position: Winger

After Wessam Abou Ali joined the Columbus Crew last year from Egyptian super club Al Ahly, could Emam Ashour also be MLS-bound?

The 28-year-old has been a starter for Egypt at the World Cup, playing on the left wing in an attack headlined by Liverpool icon Mohamed Salah and Manchester City’s Omar Marmoush.

While Ashour has a bit of an injury history, his talent is clear. He can play on the left wing, as a No. 10, or even as a No. 8 in a forward-thinking midfield. 

Potential destination: New England Revolution, San Diego FC

The Revolution need more quality in the attack, given they’ve used box-to-box midfielder Alhassan Yusuf on the wing at times. On the West Coast, San Diego need an attacking boost in the post-Chucky Lozano era and have a penchant for acquiring versatile players.

Harry Souttar

• Country: Australia
• Club: Leicester City (England)
• Position: Center back

No stranger to USMNT fans after the USA-Australia clash during the Group Stage, Souttar would bring plenty of size and experience to a backline near you.

At 6-foot-6, Souttar’s aerial ability has jumped off the page at the World Cup and at club level, where Leicester City were recently relegated from the English Championship to League One.

The 27-year-old center back may be looking for a fresh start and has several Australian teammates currently competing in MLS.

Potential destination: Houston Dynamo FC, Sporting Kansas City

In need of more talent in the back, the Houston Dynamo would be a strong option for Souttar. Plus, Ben Olsen’s use of a back three could give the Australian an easy on-ramp.

Elsewhere, Sporting KC need improvements at the back and already have Israel international Or Blorian incoming.