Luis Diaz is the first Colombian player to appear for Liverpool. Born in 1997, he was raised in Barrancas, not far from Colombia's border with Venezuela. The first time he left the country was in 2015 when he represented Columbia in the Copa America of Indigenous People, held in Chile. Diaz scored twice as Colombia reached the final, losing to Uruguay. He had now done enough to secure his first professional contract and he signed for second tier Barranquilla, an affiliate club of leading side Atletico Junior. There was no doubt about his talent but there were concerns over his ability to meet the physical demands of the game. A pasta diet, which saw him gain ten kilos, soon resolved that and by 2017 he was ready to take the step up to Junior. Diaz won the league title, reached the Copa Sudamerica final and became a regular for the national side. It was no surprise when European clubs came calling and in 2019 he joined Porto. 

Diaz earned international recognition when he was the joint top-scorer with Lionel Messi with four goals in Copa America in 2021 when Colombia finished third. Diaz continued his scoring exploits with Porto in 2021/22 with 14 goals in 18 appearances in the Primeira Liga. His speed, aggressiveness in the final third and a deadly eye for goal fits perfectly with Klopp's style of play and Liverpool were tipped to make a move for him in the summer. However, when Spurs looked to have agreed a fee with Porto in the January transfer window, Liverpool stepped in, sending a delegation out to Argentina where Diaz was on international duty to secure the deal.

Despite only arriving on Merseyside 48 hours beforehand, Diaz played half an hour of Liverpool's fourth round FA Cup tie with Cardiff at Anfield, setting up a goal for Takumi Minamino. His transition to English football was seamless and he scored six goals in 26 appearances as Liverpool ran Manchester City close in the title race. Diaz started all three cup finals, picking up a man of the match award in the FA Cup final, that Liverpool won 6-5 on penalties against Chelsea. Liverpool struggled at the start of 2022/23 but Diaz managed three goals in nine league appearances before suffering an injury at Arsenal in early October. He was expected to return after the World Cup break but broke down in a training camp in Dubai, leading to surgery which was expected to rule him out until March 2023. Diaz finally made his comeback at Leeds on 17 April, coming on for the last nine minutes of a 6-1 win. This was the first of seven straight wins, in which Diaz featured in all, that propelled Liverpool to fifth in the table and Europa League qualification. 

During 2023/24 Diaz featured in all bar one of Liverpool's 38 games in the Premier League, scoring eight goals. It was a season that contained personal trauma, with his parents being kidnapped by guerrillas in Colombia. Although his mother was found within hours it was twelve days before his father was released. This was the reason Diaz was absent against Nottingham Forest on 29 October, but his teammates held up a shirt in his honour when the opening goal was scored. The following week, despite his father still being held captive, Diaz played at Luton and scored a late equaliser, lifting up his shirt to reveal a simple message, "Libertad para Papa" - Freedom for dad.

Diaz started the 2024/25 season in tremendous form: he scored in a 2–0 win over Brentford on 25 August, followed by a brace at Manchester United in a 3–0 victory on 1 September. In the Champions League, Diaz recorded a hat‑trick in a 4–0 home win over Bayer Leverkusen on 5 November, one of the standout moments of his campaign. From 5 January to 2 April Diaz scored only one goal in 20 appearances for Liverpool but finished the season strongly with four goals in seven. He wrapped up the 2024/25 season as one of Liverpool’s featured performers, helping deliver the Premier League title with 17 goals in 50 appearances in all competitions.

Diaz was sold to Bayern Munich on 30 July 2025, after a deal worth £65.5 million was agreed. Diaz had reportedly wanted to move away since the summer of 2024 and despite two offers from Liverpool, he remained unsatisfied and departed for Bayern. His exit closed a memorable Liverpool chapter spanning three-and-a-half years, during which he scored 41 goals and laid on 16 assists in 148 appearances.