The 20-year-old is set to complete a loan move to either QPR, Leicester or Derby County today, after all three clubs made an approach to the Hammers.
The England Under-21 star has lost his first team place at Upton Park, and is currently struggling with a groin injury.
His last appearance came during the 3-0 defeat to Manchester City on January 21.
He had been a regular earlier in the season for Allardyce, while some had even suggested he had a chance of making Roy Hodgson’s World Cup squad.
Allardyce has left him on the bench in recent weeks, and has claimed many other players would have pushed themselves through the pain barrier for the team’s cause – something he feels Morrison has not been able to do.
“At the moment Rav is still complaining about the problem that he has before – these rumbling groin problems,” Allardyce said.
“He has to realise now everybody is fit there is severe competition here.
“Lots and lots of players throughout the country will be playing with a similar type of injury with the medical team saying: ‘You can carry on, it’s not a problem.’”
When pushed further on the playmaker, Allardyce let slip that Morrison had already left, and would not be involved for tonight’s clash with Norwich.
“Stop talking about Ravel. He’s not fit. He’s not here in the squad,” he added.