Reo-Coker, who played for the Hammers between 2007 and 2011, believes West Ham cannot afford to sell Carroll as they are still in danger of slipping back towards the relegation zone.
"Andy Carroll is a vital player for West Ham, even though they have picked up a few results lately, he said. "There's still a long way to go this season and he's a player they need to keep right now - for the team, the system and the way they play."
"On his day he can be a handful for even the best defenders in the Premier League and selling him in the January window is not the right thing to do," the former midfielder added. "And, despite what you might get for him, you have to remember what position it could leave your team in. Or have they someone in mind who can fit in right now?"
"For West Ham, and where they are right now, Carroll is a player they need to keep in this window."