Pompey are in talks over the sale of Tom Davies to Coventry City.
And the Blues are also hoping to offload Michael Smith and Carl Baker ahead of tomorrow's transfer window closure as they seek to create room to strengthen.
The return to fitness of Nathan Thompson has knocked Davies further down the pecking order in the fight for central-defensive spots.
Once Matt Clarke is ready for first-team action, that would leave Kenny Jackett with five centre-halves when also taking into account Christian Burgess and Jack Whatmough.
With Coventry willing to pay a fee for Davies, Pompey are hoping to reach agreement on a deal.
Meanwhile, the out-of-favour Smith has attracted interest, including bids, which at least offers encouragement to the Blues.
The striker doesn't have a Fratton Park future and the club are desperate to persuade him to move him on before tomorrow's 11pm deadline.
As for Baker, talks are continuing over reaching settlement on his contract.
Should a compromise be agreed, it will enable him to find a new club, with Coventry long-time admirers.