The 25-year-old Porto winger is attracting the attention of some of the game’s biggest clubs - and it is believed Liverpool are set to win the race for his signature ahead of Monday’s 11pm transfer deadline.
That all seems a far cry from growing up in La Guajira region of Colombia and his first steps in the game came in the Copa America for indigenous people in 2015.
Diaz had been spotted by Colombian legend Carlos Valderrama after seeing off competition from almost 400 other hopeful to secure his place in the squad.
There were, however, doubts over whether the seriously underweight youngster could cope with the physical side of the game.
Colombia coach John Diaz reflected on seeing Diaz in trials, telling the BBC: “For a moment, we thought it would be very difficult for him to perform because ‘Lucho’ seemed to have malnutrition problems.
“He was very skinny and lost the duels with other players.
“But despite that, he managed to stand out among 400 candidates and make the 26-man squad.”
Rapid development and international honours
At the age of just 17, Diaz shone during the tournament and earned himself a move to Colombian second division side Barranquilla.
His time with his club would be relatively short, and his form during his one and only season in the second tier led to a move to Liga Dimayor club Athletic Junior in July 2017.
The move did not surprise Barranquilla coach Fernal Diaz, who commented: “Lucho can shoot from outside the area, he is comfortable with both feet, he can dribble, open defences up and score goals. He can do everything.”
Diaz went from strength-to-strength, and his form with his new club led to a first call-up to the Colombia senior squad.
After making five appearances for their under-20s, the winger earned full international honours when he came off the bench to replace Juan Cuadrado in a goalless draw against Argentina in September 2018.
Catching the eye in the Copa America
Diaz had quickly acclimatised to life in international football and produced a stunning series of performances in last year’s Copa America.
Four goals in six games saw him lead Colombia to third place in the competition and brought comparisons with Manchester United forward Cristiano Ronaldo.
But one former Colombia coach likened the winger to another Old Trafford star.
“A player like Lucho, with the qualities he has, can play for any team. It’s not easy to find players like him," Arturo Reyes told O Jogo.
“There are things similar to Jadon Sancho. Both have fun on the field, they don’t feel pressure and they play the same way in any side.”
European interest and a failed move to Wales
Cardiff City were the first European club to make a move for his services and Diaz claimed the two clubs had made an agreement.
He told Caracol Radio: “Yes, there is already a pre-agreement, but I still have not said anything to them, nothing to the leaders that I agree and that I’m going to go.
“Let’s say there is an agreement between clubs, but I’m still holding back.
“I told them that I am determined to go, but I am calm and I want to do things well. If the possibility is given, it would be good.”
A move failed to materialise - but his next switch would take him to European football and after snubbing an offer from Russian club Zenit, Diaz followed in the footsteps of a number of famous Colombian players by joining Porto.
Featuring mainly on left-side of midfielder or left-side of an attacking trio, he scored 14 goals in 50 appearances all competitions during his first season in Portugal - including a Europa League goal against Rangers.
Shining in the Champions League
The following season saw Diaz made his Champions League debut and marked the occasion with a goal against Manchester City in a 3-1 defeat at the Etihad.
Life amongst the European elite has been to his liking and he scored home and away against Italian giants AC Milan in this season’s Champions League - but an impressive display against Liverpool could have ignited his biggest move yet.
Porto will need some persuading, with coach Sergio Conceicao telling O Jogo earlier this season: “I’ve been saying that the market is right by the door and I keep saying it.
“That’s my feeling. The players are training to be called up and that’s how I make the call.
“On my part, there is total focus and on the part of the players, too.
“We realise that the market arouses curiosity, there is always this final stage where there can be movements. But from what I’ve been hearing from the management, for now, things are very calm. You never know what might happen until the last day.”
That last day could be coming very soon.