The 38-year-old Argentine appeared to receive treatment for the upper part of his right leg before stepping out into the locker room on his own.
The injury occurred when Messi was dribbling on the offensive half of the field and slipped and ran into the opponent's defender Alexis Pena. Messi fell and hit the grass in frustration.
The star tried to continue after the incident, but sat down just a short while later and signaled that he could not continue.
He felt discomfort and we will not find out more about how serious the injury is until tomorrow (Sunday), said Miami's coach Javier Mascherano after the match.
Messi can console himself with the fact that Miami at least won the meeting 5–4 after penalties.
