Lionel Messi sent a scare through Argentina's World Cup preparations after requesting to be substituted during Inter Miami's Major League Soccer match against the Philadelphia Union on Sunday.

The 38-year-old came off in the 73rd minute, clutching the back of his left leg before walking down the tunnel. Miami coach Guillermo Hoyos moved quickly to ease concerns, suggesting the change was precautionary rather than the result of a serious problem.

"He was tired; the pitch was heavy and when in doubt, the standard approach is always to ensure you don't take any risks," Hoyos said.

The coach added that no medical report had been issued at the time of speaking, but described Messi's exit as a fatigue-related decision driven in part by wet and heavy pitch conditions in Miami.

World Cup question marks

Messi has yet to formally confirm his participation in the World Cup, which kicks off on 11 June and is being co-hosted by the United States, Canada, and Mexico. However, the eight-time Ballon d'Or winner is widely expected to feature for defending champions Argentina, with the tournament set to be a record-equalling sixth World Cup finals appearance for him.

Argentina's squad announcement is due next week. Their opening game pits them against Algeria on 16 June — a fixture that will draw enormous attention across Africa, with the Desert Foxes looking to make an immediate statement against the reigning world champions.

Managing the miles

Since joining Inter Miami from Paris Saint-Germain in 2023, Messi has carefully managed his minutes at club level. Hamstring problems have kept him sidelined for spells during that period, making Sunday's early exit a development that Argentina's medical staff will monitor closely ahead of the tournament.

The 2022 World Cup winner remains the focal point of Lionel Scaloni's side, and any fitness doubt surrounding him will be followed with intense scrutiny by squads and supporters around the globe — not least in Algeria, who face him in the group stage opener.