MIAMI -- Lionel Messi left the field in the 73rd minute of Inter Miami's 6-4 win over the Philadelphia Union at Nu Stadium on Sunday night, heading straight into the locker room after grabbing his left thigh.
The Inter Miami captain could be seen feeling the upper part of his left thigh in the 70th minute after taking a free kick. He immediately asked for a substitution and was replaced by Mateo Silvetti.
Messi required no additional help when leaving the field or making his way to the locker room.
The apparent injury overshadowed a big comeback win for Miami and a record eight-goal first half.
The Union raced out to a 2-0 lead with a pair of goals from Milan Iloski -- one from open play and one from the penalty spot -- before Germán Berterame pounced on a Lionel Messi cross to finish into an open net and cut into the deficit.
The Union restored their two-goal lead minutes later when Bruno Damiani poked home after Miami keeper Dayne St. Clair deflected a shot into his path right in front of goal.
Miami came roaring back after conceding a third to the Union, with Luis Suárez scoring twice either side of a second goal from Berterame to give the home side what looked like an improbable 4-3 lead at the half.
But shortly before the break, the referee was called to the pitchside monitor and after a VAR review whistled Sergio Reguilón for a handball, which Iloski buried from the spot to complete a first-half hat trick and tie the game at four.
The half-time whistle brought a close to the highest-scoring first half in MLS history.
The second half started in a torrential downpour and the game slowed down accordingly with neither side producing the same kinds of chances they did in the opening 45 minutes.
Minutes after Messi left the field in the 72nd minute, Suárez scored his third goal of the game from an unselfish assist by Berterame to give Miami the lead and ultimately all three points. Messi's Argentina teammate Rodrigo De Paul added Miami's sixth goal of the night to push the final score into a tie for the second-highest scoring regular season match of all time.
MLS will now go on an extended break as players prepare to play in this summer's World Cup, with teams returning to the field in late July. With the win, Miami goes into the break in second place in MLS' Eastern Conference on 31 points, two behind leaders Nashville.
Argentina has not named its World Cup squad yet, but Messi was fully expected to be a participant for the defending champions. They begin play Group J play against Algeria on June 16.