Guy Whittingham admitted it was two points dropped after Pompey’s hopes of finishing outside the League One relegation zone received a blow.
A goalless draw against Stevenage on Saturday maintained the Blues’ improved form, particularly at home where they have not lost for more than two months.
However, it left them two points off fifth-from-bottom Oldham – and safety – with three matches to play.
In addition, the Latics have three games in hand on Whittingham’s men.
The caretaker boss has targeted ending up outside the drop zone before the Football League apply a 10-point deduction.
Yet they are rapidly running out of time.
He said: ‘Saturday was a hard-working point.
‘Is it two points dropped? Probably – by the end of the season it is.
‘We’ve gained a point on the others above us and only have three games left.
‘Oldham have six but all we can do is keep looking forward to the next game.
‘It’s disappointing we didn’t win because we feel the home games are there to be won.
‘We felt at half-time the game was there to be won if we could just step up our energy levels a little bit.
‘We did that – but I think you also have to hand it to Stevenage as well, they defended well and were very physical at the back.
‘Any free-kicks or corners we put in they were standing man-to-man to us and put in a good defensive display as well.
‘During that bad run we had, we probably would have been delighted with a 0-0 at home – but now we’re a little bit disappointed because of our momentum.’