Richie Barker believes Marcos Painter is getting better and better in a Pompey shirt.
And the Blues boss wants another month to assess whether to reward the 27-year-old with a longer deal.
Painter signed a new one-month contract on Tuesday after forcing his way back into the first-team.
The left-back has started the last five matches and was man-of-the-match in Saturday’s goalless draw at Oxford.
Barker has been impressed with the steadily-improving displays from a player who at one time was widely-expected to leave Fratton Park this month.
Instead Painter has cemented a regular spot, last weekend keeping out new arrival Nicky Shorey from his position.
And Pompey’s manager is to keep evaluating the former Birmingham defender as his latest contract ticks down over the next month.
He said: ‘We have given Marcos another month and we will look at addressing it as that time goes on.
‘I think he needs a good run of games. We are well aware of his fitness as well as his recent injuries and he requires a good run in the team.
‘He has certainly got better as the games have gone on and Oxford was the best I have seen him play, culminating in The News giving him man of the match.
‘A big part of that was the work ethic in and about him from his team-mates.
‘He is constantly working to try to further his career and that is something I like.’
Meanwhile, Barker has played down James Harper’s presence at the club.
The former Reading midfielder is a free agent following his release from Doncaster and has trained with the Blues since Friday.
He added: ‘James has just been training with us to keep himself fit.’