Pompey are hoping to keep Ryan Fulton for their Easter fixtures.
The Blues are in talks with the Scottish FA for the 19-year-old to play against Notts County tomorrow and AFC Wimbledon on Monday.
Fulton has been called up for under-21 Euro 2017 qualifiers against France and Northern Ireland.
But it’s felt the Liverpool loanee would benefit more from senior action with Paul Cook’s side.
Paul Jones has been recalled from his loan stay from Crawley to ensure Pompey have their bases covered.
Blues boss Cook said: ‘There is still a chance Ryan could play. The club are speaking to the Scottish FA.
‘Paul has been out on loan and been excellent. If Ryan is allowed to play we’ll select from the pair of them.’