Pompey have this week returned to pre-season training but Cotterill is once again desperately short of numbers despite new signings David Norris and Jason Pearce linking up with the squad.
Cotterill has numerous other transfer targets in his sights with Bristol City goalkeeper Stephen Henderson, Derby striker Luke Varney and former loanee Greg Halford, of Wolves, currently linked with moves to the south coast.
"We've only got seven outfield lads out there at the moment but we've been busy all summer and are still very busy," he said.
"It's just a case of getting the other deals we want across the line.
"We're low on numbers at the moment but next week we'll have lads back who are away now and hopefully we'll have some others coming too, which will make us a lot stronger."