Major League Soccer returns Wednesday night for its 29th season, its first full one with eight-time Ballon d'Or winner Lionel Messi drawing adoring crowds and scoring on free kicks at will. He and his Inter Miami team start the season at home against Real Salt Lake (streamed on Apple TV's MLS Season Pass) on the same night MLS' Orlando and New England separately open the CONCACAF Champions Cup.

The defending MLS Cup champ Columbus Crew begin their defense at home Saturday afternoon against Atlanta United. Minnesota United opens its eighth MLS season Saturday night at Austin FC, its first game under new sporting director Khaled El-Ahmad. Interim coach Cameron Knowles makes his MLS head coach debut while the Loons wait for new head coach Eric Ramsay to arrive, becoming the youngest in league history at age 32.

Here are five story lines to follow:

1. Will everything turn up golden again for Argentine superstar?

Messi is back with an Inter Miami team he led to the inaugural Leagues Cup title after his stunning midseason arrival last July. He led everybody with 10 goals scored in the new competition with Mexico's Liga MX that his team won by beating Nashville in a penalty-kick shootout. Four days later Miami beat Cincinnati in another shootout, this one to advance to the U.S. Open Cup final even though he arrived too late to get his team to the MLS Cup playoffs.

This season, Miami will play in the CONCACAF Champions Club for the first time and, barring injury, Messi will contend for the MLS' Golden Boot and MVP honors.

Messi and Miami will do so with American soccer's version of a traveling rock show that exorbitantly raises ticket prices on the secondary market. That won't affect Minnesota United supporters: Their team won't play Inter Miami in MLS' unbalanced season for a second consecutive year.

The teams haven't played since the Loons' 2-1 loss at Miami on June 25, 2022 and won't be scheduled again until 2025.

2. Loons to face MLS Cup champs in March 2 home opener

The three-time MLS Cup champion Columbus Crew are back after last season's 2-1 title game victory over LAFC, and they're looking to become only the fourth team in league history to win consecutive Cups.

Nobody has done that since the 2012 LA Galaxy. Only the Galaxy (5) and D.C. United (4) have won four MLS Cups.

Minnesota United and its supporters won't have to wait long to see the Crew again: The teams meet in the season's second week, the Loons' afternoon home opener on March 2.

The Loons won at Columbus in a penalty shootout during a knockout Round of 32 game in the inaugural Leagues Cup last August.

They'll get another good look at Crew stars such as last season's MLS Cup MVP Cucho Hern Hernández, four-time champion Darlington Nagbe and 2020 MLS Golden Boot winner Diego Rossi. And coach Wilfried Nancy has the chance to become the first coach in league history to win the MLS Cup in his first two seasons.

Columbus opens its defense on Saturday afternoon against Atlanta United at home in Lower.com Field, which will also host the MLS All-Star Game on July 24.

3. Just like their league, Loons looking to get younger

The Loons' winter moves indicate new sporting director Khaled El-Ahmad intends to balance his roster by making it younger — a trend around the league in recent years — and cost-efficient, until the summer transfer window arrives for a team that expects to have money and roster room available at that time.

According to mlssoccer.com, more than 25% of all minutes played last season were by players 23 or younger. Its average age of 26 years, 129 days old per play was youngest compared to top leagues around the world. It's U-22 and young designated player initiatives allows teams to sign young players with a discount on its salary cap.

Expect several MLS players under 23 leaguewide to play for the U.S. in the Paris Olympics in late July.

The Loons' list of players 23 and under include: MF Caden Clark (20), MF Moses Neyman (20), D Devin Padelford (21), F Sang-bin Jeong (21), MF Alejandro Bran (22), draft pick D Hugh Bacharach (22), F Bongokuhle Hlongwane (23), D-MF Joseph Rosales (23), F Tani Oluwaseyi (23) and D Victor Eriksson (23).

4. Big names who signed on the dotted line

Familiar free-agent faces in new places in 2024:

• USMNT and 2017 second overall draft pick D Miles Robinson from Atlanta to FC Cincinnati.

• Two-time MLS Cup champion Julian Gressel from Columbus Crew to join Messi in Miami.

• MLS Cup starter the past two years, Canadian goalkeeper Maxime Crepeau, from LAFC to Portland.

• Goal creator Nicolás Lodeiro from Seattle to Orlando on a one-year deal.

• Striker Josef Martinez from Miami to CF Montreal.

5. Loons to face Sounders, Liga MX's Necaxa in Leagues Cup

Organizers did some tweaking in the groupings format, but Leagues Cup is coming back in 2024 for a second time after its successful 2023 debut.

So successful that MLS teams in December created a kerfuffle, saying they'd pull their teams out of the US Open Cup and replace them with their reserve teams because of schedule congestion and player fatigue. It's an issue involving too many games and too little schedule space that threatens the U.S. Open Cup and remains unresolved with the clock ticking.

In Leagues Cup 2024, the Loons will play their Western Conference rival Seattle Sounders and Liga MX Club Necaxa in the group stage of the monthlong tournament that features 47 teams from Mexico, the U.S. and Canada. It starts July 26 and ends Aug. 25.