The striker is making his comeback from a thigh strain which curtailed his original return to the sqiad after hip surgery.
"He is a big member of the squad and we are very hopeful that, over the Christmas programme, he will be a more regular member of the squad," said Calderwood.
"At that stage, he will be a lot more positive about what he can do for himself and the team.
"But, between now and then, we want to encourage him all the way and by making little steps rather than making major jumps."