The former England captain has spearheaded the Inter Miami project in recent years, with his new club entering MLS in March 2020, and it is believed Beckham wants Messi to be the man to lead the team on the pitch.
The Argentine wanted to assure Barça fans that he doesn't have any intention of walking away from the club.
Club president Josep Maria Bartomeu and teammate Gerard Pique both confirmed the validity of the rumoured contract clause, but poured cold water over suggestions that he could actually make use of the option.
Messi finally speaks on leaving Barcelona next year
He said: "Everyone has their wish list, but if you look at the way Leo and Cristiano are still playing, even at what you might think is the later stage of their careers, I don't see it ending for them". But I also don't want to have a long-term contract and only be here because of it.
"I want to win the Champions League, it's been a long time since we won it". "For me, extra money or a clause don't mean anything".
For the famous number 10, there are more important factors in football than the financial side of things.
Barcelona have suffered a huge setback ahead of La Liga game against Valencia on Saturday and champions league opener against Borussia Dortmund on Tuesday.