Brazilian winger Angelo Gabriel, who never played a competitive match for Chelsea, has join Saudi Pro-League side Al-Nassr from the Blues for £19.1m.
The 19-year-old moved to Stamford Bridge for £13m in July 2023 from Santos and spent last season on loan at Chelsea’s sister club Strasbourg, making 24 appearances.
In October 2020, aged 15 years and 308 days, he became the youngest player in the history of the Brazilian top flight when he made his Santos debut against Fluminense in the Maracana Stadium.
Chelsea have a sell-on clause for the player, who will link up with Cristiano Ronaldo and Sadio Mane at Al-Nassr.
Elsewhere, Daniel Podence has moved to Al-Shabab from Wolverhampton Wanderers for £5m.
The Portugal winger, 28, has played for Wolves since 2019, making 108 appearances and scoring 16 goals.
He was on loan to his former club Olympiacos last season.
The Saudi transfer window closed on Monday evening.
Analysis – ‘Angelo sale helps Chelsea balance the books’
BBC Sport football news reporter Nizaar Kinsella
The sale of Angelo to Al-Nassr is significant for Chelsea as it edges the club towards balancing the books.
The Blues will receive nearly £6m profit on the fee paid to Santos last summer, to take the overall total for player sales to £188.9m.
If money banked from loan fees and sell-on clauses were also publicly disclosed and included, the total is likely more than £200m.
That balances out the some £208.5m spent on buying 11 players, not including Genk goalkeeper Mike Penders and Palmeiras winger Estavao Willian, who will join in 2025.
Although Chelsea’s approach is chaotic – as one of the busiest clubs in the transfer market every summer under this new Todd Boehly and Clearlake Capital ownership – it can be both profitable and highlight that there is indeed a plan.
That plan is to sign young players who haven’t maximised their value and either wait for them to develop into first team players or be ruthless in flipping them for a quick profit if need be.
The mere association with Chelsea is believed by many within the club to raise the value of players while they also have Strasbourg, where Angelo spent last season, as a place to send players on loan before they are sold.
Eyebrows were raised when Chelsea signed Angelo, an out of form winger struggling to break into his team in Brazil in 2023, but these figures highlight the prospect of profit as a reason to sign so many young players.