Guy Whittingham wants to recruit Therry Racon on loan when the emergency window opens.
Pompey were last week planning to snare the midfielder as a free agent provided he negotiated his release from Millwall.
However, Racon’s talks over a mutually-agreed exit from The Den failed on transfer deadline day.
Whittingham must now use the loan market to get his man.
The emergency loan window comes into force on Thursday.
And the Blues’ caretaker boss is seeking to sign Racon in time for next weekend’s trip to Bournemouth.
He said: ‘We tried to get Therry as a free but the deal couldn’t be done by the end of transfer deadline day.
‘We were hoping he was going to cancel his contract at Millwall and that went on until the last minute.
‘Now it has to be a loan because we are still interested in him.
‘Obviously things aren’t certain yet but hopefully we will be bringing him in on Friday.’
Meanwhile, Whittingham insisted there have been no more developments on Svetoslav Todorov’s potential return.
Last week he admitted a switch was fading – and that situation has not improved.
He added: ‘There is nothing new since last time.
‘There are things to sort out in the Ukraine that we have nothing to do with.’