The Jamaican has been sidelined since injuring his hamstring while scoring a goal against Peterborough last month.
"He previously picked up a left hamstring injury and came back fine from that, and then picked up a similar injury on the right," physio Erol Umut told the club website.
"We joke with him that he's lucky he only has two hamstrings.
"He is working hard with the sports science department every day and is desperate to be involved over the Christmas period if he comes through with flying colours.
"We'll take him day by day. He is a very important player to us and we want to put him back sooner rather than later, but we also want to put him back at 100 per cent and not with a risk of another injury. We'll see how it goes over the next couple of weeks."