Cotterill has targeted a striker, midfielder and defender to boost his squad, two on permanent deals and the other on loan.
He has refused to reveal the identities of the trio but has long been linked with Burnley forward Martin Paterson while Derby defender Dean Leacock and Chelsea youngster Patrick van Aanholt are also reported targets.
Cotterill told The News: "There are a couple of areas where we are stocked with players and I want us to be better than we are.
"There are other areas where we are light and I want to improve those areas as well.
"As it stands at this moment in time, on our radar we've got a striker, a midfield player and a really flexible defender. That is what we are on. Two of them would be permanents and one would be on a loan."