Chelsea have signed teenager Geovany Quenda from Sporting Lisbon on a contract until 2034.
A deal was agreed between the clubs last year that could be worth as much as €52 million ($59.4 million).
Quenda remained in Lisbon last season and has now officially joined Chelsea over 12 months after the move was first announced.
- Chelsea sign Sporting pair Quenda, Essugo in deals worth up to $81M
Quenda, a Portugal Under-21 international, can play on either wing or at wing-back.
The 19-year-old told the club's official website: "It feels great to be here. Chelsea is a great team and I am excited to play here at Stamford Bridge. The club has shown faith in players like me and I am proud to be here, proud to be part of this club."
Quenda, named Primeira Liga Young Player of the Season in 2025, has made 54 appearances in all competitions for Sporting, helping them win the Portuguese league and cup double last season.