Pompey will today sign David Cotterill on an emergency loan.
The Blues are finalising a deal for the Swansea winger to stay at Fratton Park until the end of the season.
The Welsh international can operate on the right or left wing, precious versatility for Steve Cotterill among his small squad.
As part of the deal, Swansea will have the option of recalling him after 28 days.
But Pompey are hopeful the 23-year-old will remain for their final 16 games as they look to push up the table.
David Cotterill has played 16 games for the Swans this season, starting 12 of them, and scoring one goal.
He will come into the reckoning for an instant debut against Barnsley on Saturday.
And Steve Cotterill believes the former Wigan man can have an impact on his side.
He said: ‘The deal for David is pretty much done and should be completed sometime today.
‘I have not had any negative conversations from anybody to say anything different.
‘I spoke to Brendan Rodgers on Monday about getting him and since then it has been about getting it done as quickly as possible.
‘We were looking to get him for the rest of the season but what we have settled on is that after 28 days he can be recalled should Swansea wish.
‘It’s great because he offers that versatility and should be in the reckoning for us at the weekend.’
As a teenager, Cotterill moved from Bristol City to Wigan in a £2m move in August 2006.
But he struggled to establish himself at the Latics, starting just seven Premier League games during his time at the JJB Stadium.
After two goals in 21 appearances, Cotterill made the switch to Sheffield United two years later following a successful loan spell with the Blades.
Having spent just over a year at Bramall Lane, he joined Swansea in November 2009 for a club record £600,000.
Cotterill has gone on to make 38 appearances and score five goals for the Swans.
Yet he has not featured for them since starting in a 2-1 defeat at Leicester on January 3.
And Swans boss Rodgers believes time out on loan can benefit the winger.
He said: ‘David has been on the outside of the squad recently and, hopefully, going to Portsmouth will help all parties
‘He’s a player who wants to be involved in the Welsh squad and he’s not going to get in there unless he is playing games.
‘Hopefully he will get a run of games at Portsmouth and when he comes back we will review the situation.
‘David has trained very well and worked hard but, like all the players, he wants to play and I feel comfortable letting him go out to get some games
‘He has motivation to go and do well for Portsmouth, particularly when they come up against sides who we are competing with.
‘Hopefully everyone will benefit.’