Kenny Jackett insisted Colin Doyle’s Pompey presence at training this week is simply down to a ‘favour’.
The former Bradford keeper is currently training with the Blues after he failed to agree terms on a new deal at Valley Parade.
Doyle has four Republic of Ireland caps and represented his country in friendlies against France and the United States at the end of last season.
The 33-year-old is vastly experienced following spells at Birmingham, Nottingham Forest, Millwall and Blackpool.
However, Blues boss Jackett put his time with the Blues down to doing the player’s agent a good turn.
Speaking to the News, the Pompey manager said: 'It's just a favour, really.
'I know his agent very well and he's currently without a club.
‘He’s having a week’s training with us.
'We're just starting off with him this week and it's handy having a spare keeper around.
'He's experienced, though, a good guy, fitting in very well in terms of the weeks training.’
The Blues currently have summer arrival Craig MacGillvray and Luke McGee battling it out to be No1 for the start of the new season.
This week Alex Bass signed a new three-year deal at Fratton Park but will now spend next season on loan at Torquay.