The confirmation was conveyed by ICC to the England and Wales Cricket Board on behalf of the Event Technical Committee of the Cricket World Cup 2011. Morgan will replace Pietersen who has a hernia injury.
Any injury-based replacement requires a written submission to the event technical committee along with a diagnosis from a medical practitioner as to the extent of the injury, ICC said in a statement. Once replaced, a player may not return to the squad save as an approved subsequent replacement for another injured player.
Morgan is a 24-year-old middle-order batsman and has played in 38 ODIs for England in which he has scored 1,160 runs at an average of 40. Pietersen is the 14th player to be replaced in the tournament.
As with all players in the tournament, the eligibility of a replacement player is subject to approval by the ICC before that player can be officially added to the squad.