Richie Barker has urged Pompey to utilise the home advantage he believes will dictate their League Two future.
The Blues face Mansfield at Fratton Park tomorrow in a match many supporters regard as a must win.
Following the goalless draw at promotion-chasing Oxford last weekend, Pompey are faced with their first fixture on home turf of 2014.
Defeat to the Stags could even see them residing in the relegation zone come Saturday evening, if other results go against them.
Barker will put forward five points and three clean sheets from their past four matches as tangible proof he has rallied the side.
But he is fully aware of the importance of taking maximum points from a Fratton Park match against the 17th-placed Stags.
‘Ultimately, I think our home results will decide where we finish,’ said Barker.
‘We’ve got some tough away games coming up – places like Fleetwood, Chesterfield and Scunthorpe. The points we can get up there will be bonus points really, without being too negative.
‘They will be points that would be great but I think the home games will probably dictate most where we end up.
‘There were some positives at Oxford and there were also some negatives which we needed to work on and have done throughout the week.
‘It’s small building blocks. What we would like to do is keep up the unbeaten run of one defeat in four at the minute – but we are also aware we are at home and need to win matches.
‘If we don’t win tomorrow we won’t get relegated. It’s close to essential because it is really important, but it won’t dictate the rest of our season I am sure.
‘Equally, if we win it doesn’t mean we are automatically going to stay up, we’ve still got 20 games to go.
‘It is important to win, yes. It would be great for everyone’s confidence. Looking at the league table on Sunday morning would be a lot more enjoyable.’
Paul Cox’s side have won just three of their past 21 matches – all coming away from home.
That includes tasting victory in their last matches away from Field Mill – triumphs coming at Cheltenham and Exeter.
In contrast, Pompey have won just one of their past six home matches, but Barker is not convinced his players have issues lining up in front of 15,000 fans at Fratton.
He added: ‘I don’t know whether they have been affected by the crowds. I don’t see anybody who doesn’t really want to go and get on the ball.
‘We haven’t played at home since December 29, the best part of three weeks, and a lot of water has gone under the bridge since then. A lot of new people have come in.
‘Hopefully people can start to see a little bit of light at the end of the tunnel which will mean everyone’s mentality has changed.