Portsmouth chairman Milan Mandaric is refusing to rule out a shock move to bring former boss Harry Redknapp back as successor to sacked Alain Perrin.
Redknapp joined Southampton after an acrimonious exit from Pompey in 2004.
Sheffield United boss Neil Warnock is the top target, while Pompey have been refused permission to speak to Rangers' manager Alex McLeish.
And Mandaric said: "I haven't spoken to Southampton about Harry Redknapp but I wouldn't rule that out."
Portsmouth are in discussions with Warnock's advisors, and the Blades are currently weighing up whether to let him talk to Mandaric after confirming they had received an official approach.
But Rangers have rebuffed a move for McLeish, despite the fact that he is likely to lose his job after being given a brief stay of execution by chairman David Murray.
An approach for Crystal Palace manager Iain Dowie was also turned down.
Mandaric is also considering appointing a young manager to work alongside a senior figure such as Sir Bobby Robson or David Pleat.
But the emergence of Redknapp as a serious contender is a stunning development, given the acrimony of his departure and his subsequent swift move to Pompey's fiercest rivals.
Mandaric said: "I'll always speak to Harry Redknapp - we had some great times together.
Warnock is top of Portsmouth's wanted list
"There was an incident a year ago but that's no reason not to talk to him. You never say never in this situation. Strange things happen in football and I think Harry is a great guy."
Mandaric added: "There is a short list - Neil Warnock, McLeish is now out - at least for the time being - Iain Dowie, I guess he's out.
"There is a possibility of putting a young up-and-coming manager in there and giving him a senior guy to work with, someone like Sir Bobby Robson or David Pleat.
Bramall Lane vice-chairman Terry Robinson said of Mandaric's approach: "We're mulling over an approach Portsmouth have made for our manager.
"Discussions are on-going on how we will respond to that approach and at this stage there is no more I can say."
Warnock has guided the Blades to second place in the Championship but is out of contract in the summer.
The 56-year-old refused to comment on speculation linking him to Portsmouth on Tuesday, insisting he was only focused on Saturday's derby with Sheffield Wednesday.
The Blades board have an option to extend Warnock's contract, which ends in June, at the end of the season but so far have not offered to improve his terms.
Mandaric told BBC Scotland: "I also rate Alex McLeish very highly and I would love to have the opportunity to speak to him."
However, that now looks unlikely, unless the under-pressure McLeish is sacked by Rangers before a new Portsmouth manager is appointed.
Rangers chief executive Martin Bain said: "We received an approach by Portsmouth asking permission to hold talks with our manager. Permission was not granted."