Transfer journalist Fabrizio Romano confirmed the agreement on Thursday, reporting that Liverpool beat Borussia Dortmund and Barcelona to the teenager's signature. Colombian journalist Pipe Sierra had earlier broken the story, revealing that the two parties are now working through the final paperwork.
The fee is reported at around $1 million (£740,000), with Atletico Nacional negotiating a sell-on clause that gives the Colombian club a percentage of any future transfer. Martinez will sign a five-year contract with the Reds once he is eligible to do so.
Martinez was a standout for Colombia at the CONMEBOL Under-17 South American Championship earlier this year, helping his country win the title with a 4-0 victory over Argentina in the final. The result was only Colombia's second continental triumph at that age level and their first since 1993.
The 17-year-old, born in Tulúa on 5 April 2009, operates as a classic number 10 and is described by those who have tracked his progress as a leggy attacking midfielder with pace, strong running and an eye for a dribble. He stands 6ft tall and is right-footed.
At Atletico Nacional, Martinez is part of the club's youth setup and is expected to continue developing in Medellín before making the move to Merseyside. Once in England, he would likely begin with Liverpool's Under-18s and could move into the development squad as he adapts to European football.
Liverpool have been increasingly active in the South American market and have shown a clear willingness to integrate young players into senior football when they are ready. Midfielder Rio Ngumoha, who joined from Chelsea in 2024 at 17, has gone on to make 28 appearances for the first team this season.
The Martinez signing is long-term planning from a club facing immediate pressures. Liverpool are in a fight to secure a top-five finish this season under manager Arne Slot, with Bournemouth still capable of overtaking them on the final day. The summer window will demand senior reinforcements, particularly with Mohamed Salah having departed and Hugo Ekitike sidelined with injury.
The teenagers keep coming. The business on this one, though modest, is tidy.