And he has urged the Fratton faithful to embrace the Checkatrade Trophy final against Sunderland on March 31.
Pompey’s fans have long led the fight against the competition’s controversial existence.
It’s a scepticism initially emanating from the FA’s attempts to introduce B teams into the Football League.
Defeated by member clubs, it instead prompted a revamped Checkatrade Trophy in 2016-17, with under-21/23 sides brought in.
Portsmouth transfer news: Blues receive bids for former Luton and Millwall midfielder
Transfer gossip: Portsmouth eye raids for ex-Chelsea man and Charlton Athletic's former Wigan Athletic midfielder
'Is proving one hell of a signing.... A real livewire' - Portsmouth match ratings from 2-0 win at Cheltenham
Former Portsmouth pair help Ipswich flex muscle as Norwich City man is slammed for conduct in Peterborough's Plymouth Argyle reverse
Cheltenham boss Wade Elliott praises experienced Portsmouth in 2-0 defeat at Whaddon Road
Fuelled by mistrust of football authorities’ intentions, Pompey supporters have joined other fans in boycotting fixtures.
But the Blues’ chief executive believes such concerns are currently unfounded.
Catlin said: ‘I can 100-per-cent categorically say I cannot foresee B teams ever coming into the league structure during my lifetime, however long my life may be.
‘I cannot see it happening for decades in the future, there's just no appetite for it whatsoever from clubs in the Football League.
‘The opposition to it previously was so resounding. All it would require is eight clubs out of 72 to block it in the future.
‘Those rules were changed as part of the ‘trade-off’ to what is now the format of the Checkatrade Trophy. These were altered from a 75 per cent majority required among clubs to allow B teams into the EFL to a 90 per cent.
‘In my honest opinion, the Checkatrade Trophy is not being used as a back door to get B teams in.
‘If there is an attempt to get B teams into the mainstream league system, that will be a completely separate argument.
‘Plain and simple, I wish to dispel that fear.’
The Blues’ highest home attendance in the tournament is 3,138, yet the club have requested 39,659 seats for Wembley, with tickets on sale from Monday.
In terms of prize money, Pompey will make at least £190,000, dependant on how they fare in the final.
Meanwhile, the competition has this season appeased clubs by relaxing team-selection criteria.
Catlin added: ‘Wembley finals don’t come around that often, people can go a lifetime without one, so let’s take this one for what it is, enjoy it, because it may be we aren’t there for a while.
‘I think it will be a great day out. The Pompey family coming together and showing how far we’ve travelled since the dark days of administration.’