The striker, who got the FA Cup winner against Manchester United last Sunday, is primed for a £2m switch to Championship pacemakers Newcastle.
But Simon Grayson admitted: "There is a bit of concern over how the fans will react even though they have always backed the team I have put out. I would like to think that if Jermaine is here at the end of the season he will have scored the goals to get us promoted. If he goes, I would like to think I can bring in a replacement to carry on where Jermaine left off."