The MLS suddenly became part of the global football conversation, with almost every Inter Miami game sold out immediately.
Presence on their social media went from about two million to the 50 million it is today.
Average MLS crowds went up by about 20% after Messi's debut and global streaming doubled during his first 10 matches.
Just as importantly the league ceased to be a minor curiosity and became an essential part of daily sports bulletins. Americans were finally taking their football seriously.
In a system of dynamic pricing, tickets soared. Prices pre-Messi were about £40, while today they are between £150 and £200 to see Miami in action.
Sides hosting Inter Miami and Messi would change their home venue in order to keep up with demand.
On April 19, Columbus Crew moved their home fixture against Inter Miami from their Lower.com Field Stadium in Columbus (capacity 20,371) to the Huntington Bank Field in Cleveland (capacity 60,614), home of the Cleveland Browns NFL side 150 miles north of Columbus.
It was a sellout, a single-game record for a Crew home match and the largest non-NFL event in the stadium's history.
Annual club revenue grew from £41m in 2022 to £160m in 2024.
The 'Messi effect' propelled the league to a record attendance of more than 11.4 million fans in 2023-24.
His debut helped generate 300,000 new MLS Season Pass subscribers on Apple TV, doubling its base. Messi's number 10 jersey was the league's top seller, and merchandise sales grew by 41%.
The impact was also felt by other clubs, who generated an additional £63m in ticket sales by hosting Inter Miami. Furthermore, the average ticket price increased by 1,700%, with gate receipts reaching £198m.
Asensi explains: "Leo is going to be irreplaceable. There will be nobody that will be able to fill those shoes. We are trying to build that legacy to be a magnet for other good players to come."
Other initiatives to attract and develop emerging players are also in place, such as the Dreams Cup - a platform for young talent alongside the Inter Miami foundation to support youth football.