Pompey will not be blocked by the Football League from bringing back Joe Mattock and George Thorne, left.
The Blues have had to operate on a ‘one in, one out’ basis since their financial problems arose.
But Pompey boss Michael Appleton has been told that the West Brom duo can return on loan as they have already been in the club’s squad this season.
He said: ‘The situation with Joe and George, as far as I’m aware, is that because they were on the squad list at the time the troubles started, that they can come back at any time.
‘The problem is that West Brom have got a massive injury list but I’m hoping they can both return by the end of January.
‘If they don’t, then we can look at the next best thing and they could return on emergency loan.
‘They can be done. The problem is trying to get anyone else in.’