Lionel Messi was forced off after 37 minutes on his return to action for Inter Miami – but his team-mates sealed a 4-0 win over Toronto FC.
The Argentine, absent for Miami’s 5-2 defeat by Atlanta on Saturday due to fatigue, could miss next week’s US Open Cup final against Houston Dynamo.
Manager Gerardo Martino said the 36-year-old is carrying an “old injury”.
The seven-time Ballon d’Or winner was not used by Argentina boss Lionel Scaloni against Bolivia last week.
Messi’s former Barcelona team-mate Jordi Alba also suffered an injury against Toronto and Martino said both players would definitely miss Sunday’s game against Orlando City.
“There is no chance they will be there on Sunday,” said Martino.
“I know we have a final to play [on Wednesday] but they won’t go near the pitch if they can’t play.”
Miami have not lost any of the 11 matches in which Messi has featured since he joined the MLS club in July, after leaving French champions Paris St-Germain at the end of the 2022-23 season.
The score was level at 0-0 when captain Messi left the field against Toronto, but his replacement, Robert Taylor, scored twice and Facundo Farias and Benjamin Cremaschi also found the net in a comfortable victory.
“The scans [Messi] had with the national team, they didn’t show any injury. We still saved him to be safe,” Martino said.
“We don’t think he has a muscular injury. That’s also from a conversation I just had with him.
“But we have to continue being careful. We’ll look at it the next few days.”
Argentina manager Scaloni said Messi did not feature for his country last week because he “was not ready to play” and the World Cup winner “did not feel comfortable”.