Carroll initially sustained the Achilles injury on the final day of last season and spent the summer recovering only to pick up a new injury in training earlier this week.
It was feared the latest setback could rule out the striker for the rest of the season and, although that is not the case, Allardyce still felt the need to enter the market this week for free agent Mladen Petric.
West Ham are not putting a timescale on his recovery, and Allardyce told Sky Sports News: "It's devastating for Andy and ourselves.
"It's not frustrating, it is devastating, because we have gone through the process of 16 weeks to go along with specialist reports on how we deal with the rehab when Andy is recovered from this injury.
"Unfortunately for us, the specialist said there was a five per cent chance it may break down again and Andy is one of those five per cent unfortunately.
"What we have to do is make sure we treat him in the right manner as quickly as we possibly can again and get it right as quickly as we can.
"It is certainly not as serious as last time, that is the one encouraging thing but hugely, hugely disappointing for him and for us."
A loan spell at QPR to regain fitness would be mint.- dannyjohnson