Pompey are casting their eye over Jake Jervis and Nicky Shorey in training.
The duo have been with the Blues since the start of the week as boss Richie Barker weighs up making a move for the free agents.
As revealed by The News on Monday, Barker is interested in recruiting Jervis – who made three loan appearances for Pompey last season – after his exit from Turkish club Elazigspor was officially cleared by Fifa upon the opening of the transfer window.
The striker, who has a number of clubs looking at him, has been involved in training at Furze Lane since Monday as Barker assesses whether to pursue his interest.
Left-back Shorey was released by Bristol City last week after ex-Blues boss Steve Cotterill decided against renewing his short-term deal.
Currently aged 32, the former England man has made 17 appearances for the League One side this season and knows director of football Steve Coppell from their successful time at Reading together.
Now Barker is mulling over whether the pair can help strengthen his Pompey squad.
He said: ‘They have been training with us for the last few days.
‘They are just training as Nicky recently left Bristol City and Jake does not have a club and has been with us before.
‘I thought I would have a look at them and will have a conversation with them in the next 24 hours about how long they will train with us.
‘If there is the opportunity to look at people then we will do that, and if they come in and do well, then that is great.
‘Bearing in mind there have been constant storms and we have been training on Astroturf, they have done as well as can be expected.’