Former Millwall star Jermaine scored his third goal of the season against Crystal Palace on Sunday, hobbled out of the match with 15 minutes to go to be replaced by young striker Dean Bowditch after picking up a foot injury.
Speaking to the Official Club Website, Town boss Joe Royle admits he may not make the clash against Derby: "Jamma is a doubt for us with the Derby match coming up. He has taken a heavy blow on the foot and we will monitor him over the next few days to see how it goes."
Meanwhile it's hoped defender John McGreal will recover from his bout of flu in time for Saturday: "John McGreal wasn't 100 per cent against West Ham and his flu has got worse over the last two days. He has been at home in bed but we are hopeful that he will recover in time to come into our thinking for the Cup match."