The Manchester United centre-back played 63 minutes in Argentina's 2-0 World Cup warm-up victory over Honduras, his first appearance for the national side since a 6-0 win over Bolivia in October 2024.
After the match, Martínez posted on Instagram: "598 days later. Everything was worth it. What a happiness to wear the most beautiful shirt in the world again."
The road back was long and often brutal. In February 2025 he ruptured the anterior cruciate ligament in his left knee while playing for United, ruling him out for the remainder of that season. It was the latest in a series of serious injuries — metatarsal problems had already cost him significant time across the previous two campaigns.
A month after the ACL injury, his daughter Aurora was born. He has spoken about the two events running in parallel — the lowest professional moment of his career and the most significant personal one arriving within weeks of each other.
Speaking to Argentina's official streaming platform AFA Estudio, Martínez described how the rehabilitation tested him beyond the physical.
"You have to reinvent yourself because you start from zero in every sense — physically, mentally and personally."
He continued: "You feel like you're not a football player. You feel pain and think you're never going to play football again."
There was a point at which he considered stopping altogether.
"After the first two or three weeks, honestly, I didn't want to play football anymore. What happened with my foot, then the knee injury, and I thought: 'That's it, I don't want to know anything else.'"
He returned to club football eight months after the ACL injury, only for a further muscular problem to interrupt his momentum. That setback delayed his return to the Argentina squad beyond the point at which Lionel Scaloni could include him in the qualifying campaign — meaning he played no minutes in World Cup qualifying at all. Scaloni's decision to include him regardless was a statement of personal trust.
Speaking to TyC Sports after the Honduras match, Martínez was defiant about what the squad is capable of in North America.
"We understand every match is a final. You could see it in the result and in the desire of every player who came on. This team is willing to give everything."
Argentina begin their World Cup defence on June 17 against Algeria. Martínez will hope to be part of it.