OFFICIAL: Arsenal bring in Torreira
Arsenal's interest in the combative midfielder came to light last month, though the deal was put on hold due to his involvement at the World Cup.
However, with Uruguay's campaign having come to an end after defeat to France in the quarter-finals, the path was clear for the two clubs to complete the formalities on the move.
The 22-year-old is highly rated and started his career with the Montevideo Wanderers youth team in his homeland before making the move to Pescara in Italy aged 17.
The eight-cap Uruguay international's stock has risen significantly since then, moving to Sampdoria in 2015 where he became a key member of their squad.
Torreira will wear the number 11 shirt at Arsenal, becoming the fourth player to join the club this summer following the aquisitions of Bernd Leno, Sokratis Papastathopoulos and Stephan Lichtsteiner.
His World Cup exploits mean that Torreira has been given an extended break and will not report back for training with the 'Gunners' until early August.
Arsenal boos Unai Emery was delgithed with the deal, telling the club's official website: “In Lucas Torreira, we have signed a young player who is a very bright talent in the game. A midfielder with great quality, I have enjoyed watching his performances for Sampdoria in the past two seasons, and we all saw him do very well for Uruguay in the World Cup.
"He is a young player already with good experience, but who wants to keep on growing. We welcome Lucas to Arsenal and look forward to him joining us soon for pre-season.”