Ethan Ampadu will spend next season on loan at Sheffield United from Chelsea after the Blades completed a busy day of transfer business.
Wales international Ampadu, who can play in defence or midfield, joins up for the 2020-21 campaign at Bramall Lane having returned from a spell at RB Leipzig.
It marks the third signing of the day for United, who completed a double swoop for Derby County full-backs Jayden Bogle and Max Lowe earlier on Monday.
"Ethan is an outstanding young player for Chelsea, and we've worked really hard to get his signature for the season," boss Chris Wilder told United's website.
"We need to thank Frank Lampard and the people at Chelsea for helping make this happen. We've got a good relationship with them and they know we're going to take good care of him.
"It's an important season for Ethan and playing in the Premier League for us is a good move for everyone. He brings a lot of qualities to the group and he's someone we've tracked for two or three seasons."
Ampadu made his professional debut for Exeter City as a 15-year-old in an EFL Cup tie against Brentford in August 2016 and made the move to Stamford Bridge a year later.
Capped 13 times by Wales, Ampadu made just three Bundesliga appearances for Champions League semi-finalists Leipzig last term.