Pompey have approached the Football League over freeing Ashley Harris and Nick Awford from their loan limbo.
The duo were sent back from Chelmsford on Monday after boss Dean Holdsworth was sacked.
Caretaker manager Kenny Brown instead wants to focus on those permanently signed with the Clarets, ensuring the young duo returned to Fratton Park after just five days.
However, the agreement remains intact for the full month-long duration, meaning they cannot go out on loan anywhere else until that expires.
In the meantime, Harris and Awford are continuing to train with Pompey in the knowledge they will not be able to represent any other club for at least three weeks.
But Whittingham has revealed the club are consulting league chiefs in an attempt to have the loan officially ended so the players can be freed.
He said: ‘The manager left Chelmsford so both Ashley and Nick are now back with us.
‘It was purely down to a change of manager and he is going to use the players signed on already.
‘It’s a big blow for them because they are both looking to go and get some games but it means they can’t go anywhere else at the moment.
‘Now they are here for three weeks and cannot join another club on loan, which is really frustrating.
‘What we are trying to do is find out from the Football League that if all three parties agree (Pompey, Chelmsford and the players) can we cancel the loan.
‘I am waiting to find out their decision on that one.
Harris appeared as a second-half substitute in Chelmsford’s 6-0 defeat to Boreham Wood at the weekend, although Awford did not feature.