Pompey are to extend Amine Linganzi’s stay until the end of the season.
The midfielder has impressed Paul Cook since arriving as a free agent at start of August.
His month-by-month deal has now expired, but the Blues are in the process of retaining him for the remainder of the campaign.
In doing so, Linganzi will join another pre-season triallist, Liam O’Brien, in committing himself to Fratton Park for the short-term.
The 27-year-old continues to serve as cover for regular holding midfielders Michael Doyle and Danny Rose in Cook’s starting line-up.
However, the recent reversion to a 4-4-2 system also suits the ex-Accrington man, who loves to surge forward from central areas.
Cook values Linganzi’s height, power and strength, often employing him from the bench when attempting to firm up his team.
His latest appearance was in the 2-1 victory over Leyton Orient at Fratton Park, replacing Kal Naismith for a 14-minute cameo.
Earlier in the campaign, he was handed a five-game run in Cook’s side, displacing Rose from the starting line-up and generally looking the part.
However, that shuddered to a stop at Cambridge United in late October following a straight red card in the second half.
Despite their numerical disadvantage, Pompey held on to win the fixture 1-0, although, for Linganzi, his misjudged tackle on Conor Newton has proven costly.
During the subsequent three-match ban, Rose reclaimed his spot alongside Doyle and has gone on to produce a number of impressive displays.
The former Northampton midfielder has established himself as one of the Blues’ most effective recruits of a busy summer.
Yet Linganzi has edged ahead of rival Ben Close to serve as back-up, while the promising Adam May continues his loan spell at Sutton United.
He has been introduced as a substitute in four of Pompey’s past five matches and is a popular member of the squad.
In total, the one-time Blackburn Rovers player has turned out 15 times since arriving at Fratton Park on the eve of the campaign, of which seven have been starts.
Once his deal has been completed, Linganzi will be among 13 players out of contract at the season’s end.
The list also includes the likes of Enda Stevens, Gareth Evans and Kyle Bennett.