England all-rounder Michael Yardy has quit the World Cup suffering from depression just days before the quarterfinal against co-hosts Sri Lanka.
The 30-year-old Sussex left-hander, who played in three matches at the tournament, said he felt he had no option but to return home.
"Leaving at this stage of a World Cup campaign was a very difficult decision to make but I felt that it was the only sensible option for me and I wanted to be honest about the reason behind that decision," he said.
"I would like to wish the squad all the very best ahead of the game on Saturday.
"I would appreciate some privacy over the coming weeks while I spend time with family and close friends ahead of what I hope will be a successful season for Sussex."
The England and Wales Cricket Board (ECB) said they had applied to the International Cricket Council technical committee to request a replacement for Yardy.
"I would like to offer my full support to Michael on behalf of everyone involved with the England team and the ECB," said ECB managing director Hugh Morris.
"Michael has been an integral part of the England set up in recent years and while he will be missed in the knock out stages of the World Cup, our priority now is to ensure that he returns home to his family and is able to spend time recovering with a strong support network around him."
Left-arm spinner and lower order batsman Yardy had managed just two wickets at an expensive 79.50 apiece and contributed a mere 19 runs at the World Cup.
He was not set to feature in the quarterfinal in any event, having been omitted from the team that beat the West Indies by 18 runs to secure England's place in the last eight.
Yardy has though played in 28 one-day internationals since making his debut in 2006 and was a member of the England side that won the World Twenty20 in the Caribbean last year.
England had already lost star batsman Kevin Pietersen and fast bowlers Stuart Broad and Ajmal Shahzad to injury at this tournament.
Yardy's condition appeared reminiscent of the problem that forced former England opener Marcus Trescothick to retire from international cricket.