Lionel Messi will miss Inter Miami's crucial Leagues Cup match against Pumas UNAM due to a muscle issue, coach Javier Mascherano has confirmed.

The Argentinian striker suffered what Mascherano called a "minor muscle injury" in his upper right leg in Miami's win over Necaxa last Saturday.

While there is no timetable for Messi's return, Mascherano was hopeful the star would soon be back on the field.

"Within the bad news, it's good news," Mascherano told reporters.

"He usually recovers very well from injuries and above all, normally does with speed, so we will see. But clearly for tomorrow he is unavailable," he added. "But then we will see how he feels, how he progresses."

Messi, who has a league-best 18 goals in MLS matches this season, led Miami to the Leagues Cup crown in 2023 shortly after his arrival to the Herons.

Inter Miami likely need a victory over Pumas in their group stage finale to reach the quarter-finals of the Leagues Cup, which features MLS and Mexican league squads.

Should Miami reach the knockout stages, Messi would have two weeks to recover before the quarter-finals.

Miami's next MLS match is set for Sunday against Orlando. (AFP)