He arrived in the Catalonian capital from Argentina as a boy, undersized and unassuming. There was soccer to learn and treatment to undergo for a growth hormone deficiency.

His name was Lionel Messi, and he wanted to play for FC Barcelona.

More than 600 goals and 10 La Liga titles later, Messi and Barça are synonymous. One does not seem whole without the other. Go anywhere in the world, from a central African town to the streets of Manhattan, and you’re likely to bump into someone in a Barcelona jersey with a “10” affixed to the back.

That ironclad alliance, however, is about to snap.

In a decision that has sent multiple shock waves rippling across the sports world and beyond, Messi informed Barcelona on Tuesday that it was time to leave. Growing frustration with the direction of the club, punctuated by a six-goal defeat to Bayern Munich two weeks ago in the Champions League quarterfinals, pushed him over the edge.

Barcelona without Messi is like the New England Patriots without Tom Brady. In an era when athletes treat teams like leased SUVs, these two megastars stayed the course — happy in their work and handsomely rewarded as trophy cases bulged with excess.

Brady in nautical blue, red and silver, Messi in claret and blue. Transcendent figures with two decades of service apiece, symbols of civic pride, hardcore contenders for greatest of all-time in their respective fields.

Next month, however, Brady will take the field with the Tampa Bay Buccaneers. And unless Messi changes his mind, he will start the 2020-21 season next month elsewhere in Europe, albeit with a more decorated team than the Bucs.

Even if Messi stays, things would not be the same. There is a part of him that wants to move on. Players can’t hide such feelings on the field; it’s in their body language, in their decisions to track back on defense or pursue a ball heading toward the sideline. Nothing short of an overhaul of the club and roster will change that.

The front-runner is Manchester City, a move that would reunite him with Pep Guardiola, his former Barcelona manager, and Argentine forward Sergio Agüero. Paris Saint-Germain, featuring superstars Neymar and Kylian Mbappe, also could join the chase. Money is not a problem: Ownership of both clubs derives from Middle East oil interests.

The money involved is massive. The release clause — the amount a suitor would have to pay Barcelona for Messi’s rights because he is under contract until next summer — is $835 million, though such astronomical figures are deterrents more than anything else. That fee does not include his salary, which was an estimated $34 million this year.

Messi and his people believe he should be allowed to leave without the heavy financial burden of the release clause on his next team. A clause in his contract allows him to opt out after this season.

But in the year of the novel coronavirus pandemic, the end of the season is in dispute. Barcelona will claim it was May 31, the original date. But after the shutdown in March, the season resumed this summer and Barcelona was active until the 8-2 embarrassment against Bayern Munich on Aug. 14.

One way or another, Messi seems certain to leave. The idea of him coming to MLS is fantasy, though an ESPN report Wednesday said there is a proposal for him to play for Manchester City for three years, then move to New York City FC. (NYCFC’s majority stakeholder is City Football Group, the money behind the English power.)

By then, though, he will be 36. Pele was 34 when he joined the New York Cosmos in the 1970s for his professional swan song.

Meanwhile, Barcelona will carry on; it’s one of the great names in club soccer. It won six La Liga titles in the 1990s, though its continental success was limited to one Champions League trophy and a lesser cup. With Messi, Barcelona conquered the Champions League four times since 2006. Only sworn rival Real Madrid (six) has won more since the turn of the century.

This season, for the first time since 2008, Barcelona did not win any trophies: second to Real Madrid in La Liga, a quarterfinal exit in Copa del Rey and a quarterfinal humiliation in the Champions League.

For Messi, despite his age, there is still much left in the tank. He suffered a statistical drop this season, though by mortal standards, the numbers remain elite: 25 goals in 33 La Liga matches and 31 in 44 games overall. Between 2009 and 2019, he averaged 52 goals across all competitions.

No matter where he lands, his artistry with Barcelona will define his extraordinary career, just as Brady’s will forever be linked with the Patriots. The only other uniform Messi has worn is Argentina’s, in which he played in a World Cup final (2014) and won an Olympic gold medal (2008).

The sight of him wearing the colors of another club, however, will take a long time to accept.

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