Avram Grant has emerged as the favourite to succeed Paul Hart who was axed by Portsmouth on Tuesday evening.
The former Chelsea manager was appointed director of football at Fratton Park last month but Pompey's executive director, Mark Jacob, has revealed that no decision has been made.
Roberto Mancini, Alan Curbishley, Gary McAllister, Slaven Bilic, Steve Coppell and Darren Ferguson have also been linked with the post.
Jacob told the Portsmouth News:"I'm not sure where the news that Avram Grant has been ruled out has come from.
"It certainly hasn't come from me. We aren't ruling anyone out or anyone in at this stage. We also expect Avram to receive his work permit by tomorrow.
"Obviously we want to appoint a new manager as soon as possible, but it isn't a decision we're interested in rushing. It's all about planning for the long term.
"We aren't looking to appoint somebody only to have to review it again soon. It may well happen after the weekend, we'll have to see.
"We want to give ourselves every opportunity and chance to survive this season – and that means appointing the right manager.
"A long-term goal is there and there are plans in place whereby we want to achieve things not just three months down the line but also three years. The R word doesn't exist in my vocabulary, it's not an option."