Detailed: Portsmouth’s plan to compete with Sunderland, West Brom, Blackburn Rovers & Co in mega-money world of Championship

And he believes this weekend’s play-off final between Luton Town and Coventry City offers clear evidence the Blues can be competitive, as and when they finally get out of League One.

Plenty of the Fratton faithful have questioned how their club can hope succeed at the higher level, when levels of investment - and losses - are so high.

That was underlined in the last set of financial results for 2021-22 when Championship clubs lost a combined £290m and wage-turnover ratio was 125 per cent, leading to many calling its finances ‘broken’.

Cullen acknowledged the problems, but feels a calculated approach when bringing in and developing players can pay off.

He said: ‘If you look at the two clubs going into the play-offs this weekend - Luton and Coventry - they have been sensible in the way they’ve gone about it.

‘They’ve still made significant losses, but they’ve been able to ameliorate those losses by having good surpluses in player trading.

‘Technically both clubs have probably lost £7m each other the past two years.

‘But they haven’t because they have made a profit in player trading, particularly Luton in the 2020-21 season where they made £4.5m and another £600,000 profit in 2021-22. Coventry have some similar figures.

‘But it’s long-term strategic approaches to player development and recruitment, which has helped get them into the position they find themselves this weekend.’

Cullen believes the likes of Huddersfield and Brentford offer examples of clubs reaching the Premier League, by getting the model right with player trading in recent years.

If Pompey want to go down the same route it inevitably means sporting director Rich Hughes unearthing more gems - but then those players eventually being sold on.

Cullen added: ‘Huddersfield were one who traded quite well, though, even then it still required significant investment and they had some losses but they still had a very good trading model.

‘The Brentfords in League One and the Championship were making a £15m-£20m trading profit, and consistently investing in the next talent and stars to come through.

‘I think you want to go into it and you don’t always want to sell your best players, but there comes a time when it has to happen.

‘If you’ve got that then you can continue to reinvest and keep going. That’s what those clubs has done really successfully.’