Craig MacGillivray vowed there’s no room for sentiment as he prepares to face his old side.
And the keeper warned Pompey not to be fooled by Shrewsbury’s slow start to the season.
MacGillivray is out maintain the Blues’ flying start against the team he moved from in the summer.
The 25-year-old enjoyed a campaign to remember last term as the Shrews defied the pundits’ forecasts of relegation to just miss out on promotion to the Championship with defeat in the play-off final.
But MacGillivray isn’t lingering on that success and is out to improve a record of three goals conceded from six league games, with three clean sheets collected.
And there is no room to think he’s aiming to do that at his old club’s expense.
MacGlliivray said: ‘It’s another game. It’s three points at stake. Yes, it’s my old team but it’s another team in the league and it’s three points at stake. We want to win.
‘As soon as I get to the game on Saturday and the whistle goes I won’t be thinking of them as friends.
‘I will be thinking of them as someone who is standing in the way of us getting three points. And we need to make sure we beat them to get the three points.
‘I’m quite routine in how I like to do things. Ultimately it’s another game against opposition where three points are at stake.’
Shrewsbury are without a win so far this season after boss Paul Hurst departed along with a host of players. MacGillivray believes their form is misleading, however.
He added: ‘They were phenomenal last season. No-one can deny that.
‘To get third, miss out on the automatics and then get beat in the play-off final after being second favourites for relegation, was a phenomenal achievement.
‘I’m sure it will be a big season in the history of Shrewsbury. Maybe they are living a little bit still in what they did last season.
‘Sometimes you can just get new players in and it gels. I had a season like that with Walsall as well.
‘It was one of those seasons. It was one of those special seasons. I think the players who left are well into double figures.
‘I know they aren’t picking up results at the minute, but from what I’m hearing they are playing some very good football and not picking up the results.
‘They may be second bottom but there’s only six games gone. A couple of results and they can be straight up the table.’