England have to win in Adelaide and also in their final Pool A game against Afghanistan in Sydney on Friday to retain a chance of reaching the quarter-finals.
Morgan has led an unchanged side in the four matches so far, yielding three defeats and the one win over Scotland – all without Hales.
Gary Ballance, who has??scored 36 runs in four innings, would most likely be the player to make way for Nottinghamshire’s Hales.
But Morgan says he and coach Peter Moores are considering all possibilities ahead of England’s fifth match at the tournament.
“It is a big decision to change anyone in the side and it won’t be taken??lightly and it won’t be made quickly,” said Morgan.
“People can be twice the player when they are not playing, particularly when??someone is not doing well.
“Halesy is working tremendously hard and, if given the chance, I’m sure he will??take it.
“I think Gary has been a bit unlucky in the way he has got out.??He is very disappointed with where he’s at and we will reassess.”
Morgan is in no doubt as to the importance of selecting the right side to achieve a victory over Bangladesh.
“We have two games potentially before a quarter-final and we have to be??leading towards the best team that we believe can get to the final and win,” he said. “It is not an easy decision.”
Morgan also acknowledges England have not performed sufficiently well in the bowling ranks in this World Cup.
James Anderson and Stuart Broad??have just four wickets between them – and all four of England’s??seamers have leaked runs at more than six an over.
“They are exceptional bowlers and in tandem we have not been consistent enough??to put the ball in the right areas,” said Morgan.??”The guys are trying really hard to do it but??we haven’t managed to take wickets early enough.??They’re not at their very best at the moment.”