Tom Naylor admitted it would be ‘heartbreak’ if Pompey failed to clinch automatic promotion with a 90-plus point haul.
The battle for second spot remains locked in for the final round of matches, with all three candidates potentially able to break the 90-point barrier.
Naylor was a regular in the Burton side which finished League One runners-up in 2015-16.
That campaign saw Wigan capture the title with 87 points, while the Brewers ended with 85.
Presently, Kenny Jackett’s team have amassed 86 points – more than Naylor’s Burton and with three matches remaining.
Meanwhile, last term saw Wigan (98) and Blackburn (96) finish in the top two, with Shrewsbury (87) third.
Pompey themselves claimed the League Two title with 87 points in 2016-17.
And Naylor is wary of losing out on automatic promotion despite an impressive return.
He said: ‘I can’t recall a better winning run in my career and we need to keep on going and see what we get.
‘Sunderland is the biggest game of the season, it’s massive, and we’ll go there with belief once again and see what happens.
‘When I got promoted with Burton from League One it was 85 points. We’ve just gone past that and there’s three games left.
‘It will be heartbreaking to hit the 90s and not get promotion, but that’s just the league this season.
‘Last year Wigan had 98 and Blackburn 96, they ran away with it. Nobody else reached the 90s.
‘There are nine points to play for and we have to win them all. At the start of the season we set out for promotion – and want to fulfil that.
‘Everyone knows we had a really sticky patch in January, but we have overcome that with wins, while the Checkatrade Trophy was a massive confidence boost for everyone.’