Chelsea have completed the signings of Sporting Lisbon youngsters Geovany Quenda and Dario Essugo in a £62.4m double deal.
The Portuguese side confirmed the transfers with Quenda's move costing the Blues £43.7m.
Sporting revealed Essugo will move to the Premier League side for £18.7m, with the midfielder moving this summer.
Quenda, a Portugal Under 21 international, will stay at Sporting next season before moving to Stamford Bridge in the summer of 2026.
January saw Man United explore a deal for Quenda, who turns 18 in April and previously played under their now head coach Ruben Amorim at Sporting.
United were said to have been tracking Quenda before Amorim was named the club's head coach in November.
After spending time in rivals' Benfica's youth academy, Quenda joined Sporting in 2019 at the age of 13.
Amorim immediately earmarked Quenda for his potential, and he became the youngest player ever to represent Sporting's reserve team at the age of 16.
At the start of the current campaign Quenda was integrated into Sporting's first-team, with Amorim raving about his performance at right wing-back after impressing in a pre-season friendly.
'He's very talented, very mature and understands the game like an adult,' Amorim told Sporting TV in July.
'He obviously has a lot to improve on, but I think he had an excellent game and we have a player there.'
Born in Guinea-Bissau, Quenda chose to represent Portugal internationally and has featured at both U17 and U21 age groups internationally.
In August Portugal boss Roberto Martinez handed Quenda his first senior call-up for Nations League clashes with Croatia and Scotland, though he did not feature in either game.
Quenda has played 44 times this season, scoring twice and setting up eight goals.
Amorim used him in a wing-back role towards the start of the season but he has since been redeployed higher up on the right wing.
Essugo, who is also a Portugal U-21 international, has been on loan at Las Palmas this season.
Chelsea have been tracking the ball-winning midfielder for some time and expect him to provide squad depth ahead of another hectic season, following on from the Club World Cup and inevitably place strain on the likes of Moises Caicedo.
Essugo hails from the same agency as Caicedo and Kendry Paez, the 17-year-old who is joining Chelsea this summer from Independiente del Valle.
The double deal continues Chelsea's push to sign top young talent under Todd Boehly and Clearlake Capital, with the ownership approaching a spend of close to £1.3billion since the takeover in 2022.