Starting his career in his native Columbia, Diaz had success at an early stage, winning the Columbian top-flight title with Atletico Junior and earning his first Columbia cap in 2018. This led to interest from Europe, with Porto eventually gaining his signature for a €7 million fee.
In his first two seasons in Portugal, Diaz settled in well with 34 goal involvements in 89 games. This equated to trophies on the pitch, with a league and cup double in his first season plus a run to the Champions League quarter-final last campaign, only losing to eventual winners, Chelsea.
It was the first half of the 2021/22 season, however, where Diaz took on a starring role at Porto which led to his move to the Premier League. In 27 games for Porto, Diaz had 22 goal involvements, including 16 goals, equating to a goal involvement every 101 minutes. Averaging 3.5 shots per game, it means that Diaz has a shot conversion rate of 35%, one of the highest seen in Europe this season and highlighting one of his key strengths, his finishing.