The fee is around £750,000. The contract is five years. Martinez will move to Merseyside when he turns 18 in April 2027, with Atletico Nacional having negotiated a sell-on clause to protect their interests in the event the teenager fulfils his considerable promise.
Fabrizio Romano confirmed the deal on 22 May, with Colombian journalist Pipe Sierra the first to break the story. Liverpool beat Borussia Dortmund, Barcelona and a host of other European clubs to secure his signature.
The question is why a club of Liverpool's standing moves this early, and at this scale of ambition, for a player yet to make a senior appearance. The answer lies in what Martinez has already demonstrated — and the environment that produced him.
At the 2026 CONMEBOL Under-17 South American Championship, he was the controlling presence Colombia needed. He wore the number 10, started five of six games, contributed three assists including in the semi-final and final, and lifted the trophy after a 4-0 demolition of Argentina in the decisive match. Reports from Colombian football media described him as the team's tactical compass — a rare description for a player of his age, usually reserved for midfielders who manage tempo rather than those who simply run hard and pass quickly.
Martinez is both. At 1.84 metres, he has the physical presence of a player several years his senior. He combines that frame with the technical qualities his academy at Atletico Nacional specifically develops: line-breaking passes, aggressive forward runs, comfort under pressure. He can play as a deeper organiser or arrive higher up the pitch as an interior midfielder in transition. That flexibility matters to Liverpool, whose midfield philosophy has always demanded positional intelligence alongside physical output.
There is also a personal dimension that speaks well of how seriously he takes his development. He is the son of Jairo Martinez, a Colombian striker who played professionally during a career that took him abroad. Those who work with Samuel point consistently to an understanding of elite football environments that is unusual in a teenager — a product both of that upbringing and of Atletico Nacional's academy, one of the most respected in South American football.
He has already captained Nacional's youth sides and has been singled out in Colombian media as a generational personality — someone whose character is as significant as his talent.
Liverpool's strategy in South America has become increasingly deliberate. They identify elite prospects before European competition inflates the price beyond reach. Luis Diaz arrived from Porto. Darwin Nunez from Benfica. The club now monitors the pipeline further upstream. Martinez represents the logical extension of that thinking — secured for under £1 million before the market caught up.
Whether he arrives at Anfield in 2027 as a developing academy prospect or fast-tracks his way into senior consideration will depend on what the next twelve months of his career produce.
The instinct to move now, at this price, suggests Liverpool believe the upside justifies the wait.