The news was announced via the club’s official Twitter account on Wednesday night as the Saints have moved quickly to replace Morgan Schneiderlin, who completed his transfer to Manchester United at the start of the week.
— Southampton FC (@SouthamptonFC) July 15, 2015
Clasie was earmarked as a potential replacement for Schneiderlin when it appeared the Frenchman was edging closer to the St Mary’s exit door and is set to be reunited with manager Ronald Koeman, under whom he played at Feyenoord between 2011 and 2014.
The 24-year-old was a member of the Holland squad that finished third at last summer’s World Cup and has made 11 appearances for the national side.
Last season he stared all but one league game for Feyenoord and found the back of the net twice and registered six assists.