Delgado in English will be playing for England at Euro 2016, after the club announced it was parting ways with the forward who made more than 400 appearances for the English club and its youth sides over two decades.
In his four years at the Stade Velodrome, the 25-year-old scored 23 goals in 79 appearances for England’s Under-19s, the senior side, and has also represented the Republic of Ireland.
He is set to return to his native Spain, where he spent three seasons with Real Zaragoza.
The decision to leave England came at the end of the summer, when the national team was under increasing pressure over the handling of player’s contracts.
“It is an incredible day for England,” Delgado said in a statement on Monday.
“Delgado has been a great asset to our football club and we wish him every success for the future.”
England’s squad will play Germany on Sunday (local time) at the Millennium Stadium in London and Germany on Tuesday (local) at Wembley Stadium.