A fourth consecutive campaign in the bottom division lies ahead for the Blues following last month’s play-off heartbreak.
Barton believes they will approach the challenge a stronger side, armed with vital added experience.
The 25-year-old had never featured in League Two before last term – and he wasn’t alone among his team-mates.
Paul Cook’s Pompey had also been constructed on the back of 14 new players arriving last summer.
And Barton is adamant the team is a more powerful unit 12 months on – and better equipped to finish in the top three.
He said: ‘We will have a far better chance of promotion this season.
‘A lot of players last year had never played in League Two, some didn’t know what to expect and for the first couple of months we didn’t know the way the manager wanted to play and had to get used to it.
‘Now everyone will be bang at it. We know what we need to do from the word go.
‘You can have bags and bags and bags of experience playing for a Championship side but dropping down to League Two is a completely different ball game.
‘It is almost like starting all over again, finding your feet and taking a couple of months to get used to it.
‘Now we have done that there is no excuse not to go and get promoted.
‘A lot of us have played together now.
‘It’s not like last season when the gaffer brought in a full team.
‘All he is doing is tweaking it and adding to it and it is only going to make us stronger.
‘Not getting promoted next season will be the biggest failure of a lot of people’s careers because we won’t have a better chance.
‘We’ve got the manager and we’ve got the players, so what is the excuse?’
Cook’s overhauled squad finished sixth last season, losing to Plymouth Argyle in the play-off semi-finals.
It was a big improvement on the previous campaign when the club recorded its lowest position in its Football League history. Despite not escaping the division, Barton insists there were plenty of positives during his maiden Fratton Park season.
He added: ‘You have got to see where the club have come from.
‘They finished low in the table the previous campaign and then we get to the play-offs with a brand new team.
‘So you have to take that as a positive.
‘Yes we were favourites to win it last season.
‘But all the hype of that – having previously finished in the bottom half of the table – was strange.
‘You cannot just jump to the top of the table straight away, you have to take steps.
‘And I think it can only get better this season.’