He has refused to reveal their identity and added he will not be rushed into making purchases.
The Blues boss is also thought to be considering a move for Bradford City winger Jamie Lawrence.
He said: "We've been trying to bring a couple of people in to try and give us a hand. It hasn't come to light just yet but we are still hopeful something might happen.
"I'm not just going to bring them in for the sake of it because they've got to be better than what we've got already and be an asset to us in the future.
"We've made bids for two players, but it would be unfair to mention the clubs involved because one of them in particular is coming back to us this week and both of them play in their respective teams."