(CNN) -- English club Chelsea have completed the signing of Oriol Romeu from Spanish and European champions Barcelona.
The 19-year-old is currently playing for Spain at the World Under-20 Championships in Colombia and has signed a four-year deal with last season's Premier League runners-up.
The deal is worth $7 million and includes a buy back clause, set at $14 million after the first year and $21 million after the second.
Romeu started his career at Barcelona's city rivals Espanyol before joining the Camp Nou academy in 2004.
The midfielder, who can also play in central defence, made his debut for Barcelona in last season's Spanish Supercup match with Seville and got his first taste of league action against Deportivo in May 2010.
He has played 90 minutes in both of Spain's games at the World Under-20 Championships, when they beat Costa Rica and Ecuador.
Chelsea official web site confirmed the signing and said Romeu is "renowned for his strength and his expansive passing ability."
Another player leaving Barcelona is Jeffren Suarez after he agreed to join Sporting Lisbon.
The Portuguese outfit have paid $5 million for the 23-year-old which, like the Romeu deal, includes a buy back option.
Jeffren joined Barca from Tenerife in 2004 and made his debut for the Catalan club in the 2006-07 season.
He told the club's official web site: "I know that the slogan of my new club is strength, dedication, commitment and glory and from today onwards I will do all in my power to make these things come true."
Barcelona also confirmed that Argentinean defender Gabriel Milito can leave the club on a free transfer.
Meanwhile, Juventus have confirmed they have rejected a bid from Russian club Zenit St Petersburg for defender Leonardo Bonucci.
The 24-year-old joined from Bari at the beginning of last season and a statement on the club's web site said they wanted to keep hold of the player.