Messi opened his account at Russia 2018 with a goal in Argentina's crucial 2-1 win over Nigeria.
The star forward struggled at the World Cup before that classy strike, which helped Jorge Sampaoli's men clinch second spot in Group D.
Messi, 31, later revealed he wore a red ribbon, sent to him by a reporter's mum after his team's draw with Iceland, around his left ankle.
"Look," he said, showing the ribbon under his sock when asked about it by the stunned reporter.
Argentina, which has struggled so far in Russia, had Marcos Rojo to thank for progression after the defender's 86th-minute winner against Nigeria.
Sampaoli's team faces France in the round of 16 in Kazan.