The Gills have been without a manager since May following Andy Hessenthaler's resignation after failing to guide them into the npower League Two play-offs.
"I'm under no pressure time-wise to finish the process other than the fact that we would very much like to have a manager in by the start of pre-season," Scally told BBC Radio Kent.
"There's no rush, I know fans may be frustrated but it's a time-consuming process and it's important that we look at all opportunities and all combinations."
Gillingham's first pre-season fixture is scheduled for July 21.
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