Lionel Messi was forced off the pitch during Inter Miami's thrilling 6-4 triumph against Philadelphia Union on Sunday evening, departing in the 73rd minute after clutching the back of his left thigh.
The 38-year-old Argentine had been instrumental before his exit, contributing two assists including one for German Berterame.
However, he signalled to the bench for a replacement shortly after taking a set piece.
The eight-time Ballon d'Or winner walked directly to the dressing room accompanied by medical staff rather than remaining on the substitutes' bench, immediately sparking anxiety among supporters with the FIFA World Cup now less than three weeks away.
Lionel Messi had to come off against Philadelphia Union with a hamstring injury
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Inter Miami confirmed on Monday that subsequent medical examinations had diagnosed an overload linked to muscular fatigue in Messi's left hamstring, with tests ruling out any significant tear.
The MLS club stated that the captain's return to training would depend entirely upon his clinical and functional recovery, declining to specify a precise timeframe.
Interim manager Guillermo Hoyos sought to ease concerns following the match, attributing the issue to tiredness and difficult playing conditions.
"He was tired, the field was heavy, and rather than doubt, you always say not to take the risk," Hoyos explained.
The Argentine departed the field unaided and showed no signs of serious damage whilst making his way towards the changing facilities.
Concerns over Lionel Messi's injury have been eased by manager Guillermo Hoyos
|REUTERS
The timing of Messi's setback introduces uncertainty just one week before Argentina assembles for their pre-tournament training camp ahead of their World Cup title defence.
Lionel Scaloni's side face Algeria in Kansas City on 16 June in their opening Group J fixture, with the expanded 48-team tournament commencing on 11 June across the United States, Canada and Mexico.
Argentina's squad is expected to be announced next week, with the defending champions scheduled to face Honduras on 6 June and Iceland on 9 June in warm-up matches on American soil.
Despite the absence of a confirmed recovery timeline, Messi remains widely anticipated to lead his country in what would be his sixth World Cup appearance.