Boss Jim Magilton says he could make a second bid for Leicester defender Gareth McAuley over the weekend. The Blues had an initial offer refused by the Foxes last week.
Magilton has already made a second bid for Plymouth's David Norris and told the club site that he hasn't given up on signing Northern Irish international McAuley: "We are monitoring the situation and maybe something will happen over the weekend.
"But if things don't work out with those two then we will turn our attention elsewhere."
Magilton says he doesn't know whether Plymouth will accept his second bid for Norris: "We have now made a second offer for David Norris and we will see where that takes us.
"It's a good offer, but I don't know if Plymouth want to sell the player. He's loved by the supporters down there, so there is a bit of fan power.
"He's also a very good player and I can understand why Paul Sturrock doesn't want to sell him. We've made the second offer now though and, while I have not set a deadline, there will come a time when we have to make a decision and that will be pretty soon."
Magilton has also ruled out links with his former Northern Ireland team-mate Neil Lennon and Blackpool's Wes Hoolahan. The Irishman is expected to join Sheffield United, who have been strongly linked since before the transfer window opened.