Morgan ruled out of final ODI
Morgan first felt pain during the fourth one-day international at Adelaide on January 26 but played the next two matches at Brisbane and Sydney. However, the problem has got worse over the past week and an x-ray confirmed the nature of the injury. He will fly back to the UK and see a specialist before his World Cup future is decided.
"Morgan will return to the UK and will see a specialist to determine the full extent of the injury and a treatment and rehabilitation schedule," an ECB statement said. "A decision about his participation in the World Cup will be made following the specialist's assessment of the injury."
Although Morgan has had a poor one-day series against Australia, making 106 runs at 17.66, his absence for the World Cup would be a major blow after he established himself as one of the finest finishers in the game since switching his national team from Ireland to England.
It also creates the potential of a serious headache for the England selectors with fitness clouds hanging over a host of players. Graeme Swann (back), Tim Bresnan (calf), Ajmal Shahzad (hamstring), Paul Collingwood (back) and Chris Tremlett (side) have all flown home early from Australia and all except Tremlett are in the World Cup squad.
Andy Flower said on Friday that Bresnan was the most serious concern and with Morgan's injury there is a real chance England won't have 11 fit players available for the warm-up matches against Canada and Pakistan. Swann and Collingwood have been granted paternity leave and won't arrive until two days before the opening group match against Netherlands on February 22 even if they are passed fit.
Before the news of Morgan's injury was revealed, Andrew Strauss said he was looking forward to having a full-strength team back together after his depleted side was comprehensively beaten by Australia. "The injuries are a bit of a setback, but it looks like the guys are going to be fit for the World Cup so in some ways it might be a blessing in disguise."
Morgan's absence also means a weakened batting order for the final ODI against Australia with the likelihood that Michael Yardy will have to bat at No. 6 and Luke Wright at seven.
Andrew McGlashan is an assistant editor at ESPNcricinfo