Allen has admitted that he wants to raise funds in order to make changes to his squad.
"I need to make changes, to add players and the group needs to be freshened up," he told BBC Radio Kent.
"I've also told all the others that after Sunday's game, I'll have a view to making potential further changes. We need to improve our starting XI and we need to get better.
"We need to raise some money to improve our team. They're great lads, all four of them, and they've done a great job for our club, but changes need to be made."
Gillingham face Coventry City on Sunday.