Pompey are facing a selection headache ahead of their FA Cup clash with Notts County.
Michael Appleton is currently waiting to discover whether Carl Dickinson will be allowed to feature on Saturday.
They have already lost the services of loanees Scott Allan and Mikkel Andersen.
The duo’s parent clubs have stepped in to stop them becoming cup-tied.
In addition, Darel Russell remains unavailable as he continues to recover from a hamstring injury.
Should Dickinson also be denied permission, that would leave Appleton with a squad of just 16 for the first-round fixture.
The left-back is one of three loans at Fratton Park.
West Brom have already announced they don’t want Allan to play.
Similarly, Reading have rejected permission for Andersen to feature, opening the door for Simon Eastwood to deputise.
Watford are currently weighing up whether to also stipulate Dickinson cannot play in the Fratton Park match.
Before his Pompey arrival, he had drifted well away from the first-team scene at Vicarage Road with just a solitary Championship start this season.
However, he did play in both the Hornets’ Capital One Cup games before they were eliminated by Bradford.
Now Appleton is hoping they will see fit to allow him to play his third successive match for the Blues during his initial month’s stay.
At least Pompey have Brian Howard back from a one-match ban to bolster the midfield.
They also have cover at left-back in the form of Adam Webster, Mustapha Dumbuya and Jon Harley.
Meanwhile, Eastwood’s anticipated appearance will be his third in three different cup competitions this season.