Liverpool midfielder Steven Gerrard has retired from international duty.Gerrard, who turned 34 in May this year, captained England during a disappointing 2014 World Cup in which they crashed out of the tournament at the group stage.The Anfield veteran, who made his debut for his country against Ukraine back in May 2000, represented the Three Lions 114 times and scored 21 goals."This has been a very difficult decision, one of the toughest I've had to make in my career," Gerrard told the FA's official website."I have agonised over this since coming back from Brazil and have spoken to family, friends and people close to me in the game before coming to this point. "Most importantly, Brendan [Rodgers, Liverpool manager] has been fantastic and obviously I have to look after my body as much as possible to ensure I can give everything when I take to the field. "To ensure I can keep playing to a high level and giving everything to Liverpool Football Club I believe this is the right decision, and having Champions League football back at Anfield is another big factor in my decision."