Phil Smith has been assured he is not regarded as a goalkeeping back-up.
But Guy Whittingham is adamant current first-team regular Simon Eastwood remains his number one.
Smith arrived at Fratton Park in December as a free agent but has yet to make an appearance.
Eastwood, by contrast, has established himself as Whittingham’s first choice.
However, a costly mistake in the defeat to Oldham did spark calls from fans for Smith to replace him.
Eastwood, though, kept his place against MK Dons in the week and proved confident and reliable.
For the caretaker boss, though, Smith continues to put pressure on Eastwood for the goalkeeper jersey.
Whittingham said: ‘Eastie is our number one. He made a mistake at Oldham but has kept us in games at times this season.
‘I have got no qualms that if Eastie ended up being costly for a few games in a row then Smithy will get his chance.
‘He’s not here just to be a training partner. He will step in, for sure.
‘Smithy has looked fine in training, has always looked sharp and trained well so I wouldn’t have any worries about putting him in.
‘He’s okay. I think at some stage he would like to think he could get into the team but Eastie has done fine.’
Pompey, however, do remain light on keepers.
The Academy’s Connor O’Hara was recently released from the club by mutual consent.
Youth stopper Claude Da Costa is presently sidelined by a long-term back injury.
It means Paul Hardyman’s side is relying on Lewis Ward, who is on loan from Reading.
Whittingham added: ‘With the first team, we wouldn’t go out and get another goalkeeper in, it wouldn’t be a loan we are thinking about.
‘And in the position we are, I think it would be wrong to bring a youth goalkeeper in even if we had one.’