And the Blues’ assistant manager warned his team need to guard against those sides desperate for points to avoid the drop.
Pompey’s next four games are all against side outside of the top 10.
Gillingham visit Fratton Park next weekend before Kenny Jackett’s men go to Oldham. Oxford then arrive in PO4 before Pompey go to the Bescot Stadium to face Walsall.
Pompey also have to face the current bottom two in Bury and Rochdale before the end of the campaign.
With the season intensifying Gallen feels that narrative can impact the sides in the top half, as will the fact many players are facing uncertain futures.
Gallen said: ‘Normally around March time the teams at the bottom can come up with results. Everyone down there is fighting for their lives.
‘Players are fighting for their team against relegation and players are also fighting for contracts. That can be a big motivator.
‘There’s teams looking at automatic promotion and sides looking at the play-offs.
‘It can get a bit nervy. It’s something we need to be aware of.
‘We want to put pressure on the teams above us.’
Pompey surprisingly still find themselves just four points outside of League One’s top six. But talk of the play-offs is weighing heavy on supporters with just two league wins this year.
Gallen feels Pompey have to guard against focusing on looking too far down the fixture list, however, when assessing what’s required over the remainder of the campaign.
He said: ‘I think if someone said we had to win seven or eight of the next 11 games, that could be a tall order or slightly daunting.
‘You have to break it down. It’s always just the next one.
‘Can we win the next game? I think we can.
‘I’m not saying we’re going to, but we’re capable.
‘Our performances at home have been pretty consistent.
‘Not so away from home, but our performances at home have largely been okay.
‘Against Blackburn I felt we deserved a draw. We didn’t get it, but looking back and analysing the game you can see we were more than a match for them and played pretty well against a good side.
‘The way of looking at it is looking at the next game. Can we win it?’
– JORDAN CROSS