The Inter Miami star will turn 39 during that tournament, which takes place in the United States, Canada and Mexico in two years' time. 

The eight-time Ballon d'Or winner has seemingly left the door ajar to a final swansong at the world's biggest international tournament, though he admits his participation will be dependent on how he feels as he edges closer to the end of his glittering career. 

"It depends on how I feel, on how I am physically," Messi said in an interview with Infobae.  "I have to be realistic with myself and know if I am up to the task of being able to compete and help the team-mates next to me. There is some time left, and I don't know how I will be at that moment. 

"Age is also a reality, although it is a number, and the games that I am going to play [at Inter Miami] are not the same as the ones I played when I was in Europe. 

"It will depend on how I feel, what I feel when I'm next to my team-mates, and I'll see if I'm still up to par or not."

Messi has 12 goals and nine assists in 12 MLS appearances this season, with the Argentina captain set to lead his country's bid to retain its Copa America title in the coming weeks.

La Albiceleste kick-off their campaign against Canada on 20 June at the Mercedes-Benz Stadium in Atlanta, and Messi believes the competition at this year's tournament is as strong as it has ever been. 

"I think that Argentina is always favourite," he said. "When a tournament starts, be it a World Cup, Copa America or whatever, Argentina is a candidate just like Brazil and more so in this Copa America. 

"But I think that today the South American teams are very strong. Uruguay are very good, as are Colombia and Ecuador. I think it will be a very level Copa America."

Lionel Scaloni will take charge of Argentina at a fourth international tournament and will be hopeful his number 10 can lead them to glory once more. 

Amid talk it could be Messi's last competition with his country, Scaloni wants supporters to focus on the present, rather than looking to the future. 

"We Argentines are too melancholic," he said. "We are already thinking about the day when he is not there, when he is still playing.

"Let's enjoy it and we'll see tomorrow, because I think the present is so important, not only for Argentina, because, in the end, Leo plays for those who like football. Someday it will happen."