The striker, signed from Liverpool for €19m last summer, has suffered another setback as he bids to complete a full season at Upton Park and is struggling to deal with the blow
The 25-year-old striker, who joined the Hammers from Liverpool for €19 million last year, is currently sidelined with an ankle injury that will see him miss the start of the Premier League season.
Having also missed a large part of the 2013-14 campaign, Carroll is struggling to come to terms with his latest setback.
"He is pretty miserable," Allardyce admitted to reporters. "He is not very happy with life at the moment because it is a massive blow to him again.
"We just have to pick his spirits up. Hopefully when the boot comes off and the specialist gives him the okay to start working again he will feel a lot happier with himself.
"But he is certainly very upset and very miserable at this moment in time."
Ecuadorian forward Enner Valencia joined the club earlier this summer but he too will miss the start of the 2014-15 campaign.