The teenager last week signed a 12-month extension to keep him at Fratton Park until the summer of 2019.
It is understood the new deal does not contain a minimum release clause.
The four-goal striker remains a firm Fratton favourite and the Blues’ most bankable asset, bearing in mind age and potential.
Chaplin has unequivocally indicated his desire to stay by signing a second deal in the past 13 months.
And chief-executive Catlin is adamant the club also have no intention of selling him off.
He said: ‘It’s important for supporters to realise I am in contact with chief executives on a pretty regular basis on a range of different issues at clubs.
‘There are always people asking how certain players are doing at your club – and Conor is no different to that.
‘In my mind, what constitutes interest is an actual bid. We have not had any bids and it’s not something we are looking for.
‘We want Conor to develop with us, and as long as Paul Cook wants him at the club then he will stay and continue helping us progress.
‘This isn’t just about the player, this is about Portsmouth Football Club and, while we have got to respect and recognise individuals, it’s a team game and vitally important we as a club get to where we want to be.
‘Conor is really happy here, he is enjoying his football and has scored four goals already this season.
‘This was a very straightforward and simple extension to his existing contract.
‘He jumped at the chance, which is credit to him and credit to his agents, who said one of the vital things for Conor at the minute is playing games and developing at a good, steady pace.’
The deal rewards Chaplin for his continued progression with Pompey, having emerged through the ranks.
He netted 11 times last term during a first full campaign, while has registered four goals in his past eight outings.
And Catlin revealed the youngster’s wages are now on parity with other first-team members.
He added: ‘You don’t want them running into the final year of their contract otherwise the balance of power then shifts to the player. So you are always looking to give yourself that breathing space.
‘This deal puts Conor favourably in line with others in the squad.
‘When someone comes through your Academy there tends to be a year or two when you assess how far they have developed before you get to the point where you have to treat them exactly the same financially as other players in the squad.
‘Conor has reached that point now.
‘He didn’t make lots of demands, he is settled in the area, is very happy here and enjoying his football.’