John Coleman has admitted it has been the most frustrating summer for getting players in.
The Reds have signed Will Wood (Southampton), Piero Mingoia (Cambridge), Sam Finley (Fylde) and Offrande Zanzala (Derby) ahead of their League One opener at home to Gillingham on Saturday but Coleman has made no secret of his hunt for another goalkeeper, a defender and two strikers.
Meanwhile other clubs are casting admiring glances at his players, with Janoi Donacien signing for Ipswich this week, while the club have turned down a couple of bids for striker Kayden Jackson.
"It has been the most frustrating summer I have had in terms of recruitment both mentally and physically," said Coleman.
"We have been looking to take players on loan but due to the World Cup players are coming back late, so Premier League clubs are keeping hold of all their players for longer.
"It is part and parcel of the job though and if you don't like it, don't do it.
"We have turned down bids for Kayden and you do end up spending a lot of energy on that.
"There is a scarcity of strikers, that in itself adds to his value and the way he has performed in pre-season again adds even more value.
"I would love to keep him obviously but it could be taken out of my hands - we will see what happens."