The son of a professional footballer, Del Rey won the Spanish U-16 and U-18 titles and was became a member of the Spanish national team at the age of 14. Was a key member of the side which won the European Amateur Team Championship in 2017 alongside fellow DP World Tour members Adri Arnaus, Manuel Elvira and Angel Hidalgo. Also represented Spain at the 2018 Eisenhower Trophy and the International Team at the 2019 Arnold Palmer Cup.

Attended Arizona State University from 2016 to 2020, winning four times in his collegiate career with the Sun Devils.

Won on his third start after turning professional in 2020, claiming the Open de la Mirabelle d'Or title on the Alps Tour. Joined the Challenge Tour in 2021 and earned his first victory the following year at the Big Green Egg German Challenge.

Set the record for the lowest ever round to par on a major golf tour with a 14 under par 58 at the 2021 Swiss Challenge, carding eight birdies and three eagles.

Ended the season 22nd on the Road to Mallorca Rankings, narrowly missing out on his DP World Tour card, but earned his playing rights at Qualifying School after finishing fifth at Final Stage.

Earned his maiden DP World Tour victory at the 2025 Ras Al Khaimah Championship, winning by four strokes at Al Hamra Golf Club.