The Wigan loanee has been a bit-part player since arriving on January transfer deadline day for the rest of the season.
Vaughan has made just seven appearances off the bench after finding himself behind Omar Bogle and Oli Hawkins in the striking pecking order.
Having recovered from a minor back injury, the former Everton man has been an unused substitute in the Blues’ past two games.
He was left on the bench for the Checkatrade Trophy final triumph over Sunderland on Sunday – despite Jackett having the option of making an additional change in extra-time.
The boss admits Vaughan has been frustrated but believes the 30-year-old’s chance will come.
Jackett said: ‘James is disappointed but is still very much in the mix.
‘There’s still a lot to play for and we want to be as strong as possible.
‘For James, he’ll be waiting for his chance and waiting for his opportunity.
‘And when he does get it – because he will get it – he has to take it.
‘It has been in my mind to start him. In terms of our strength in that position, we want that sort of competition.
‘We want them to spur each other on – that’s a big thing.
‘The forwards we have are different types of players and we have got a strong bench to be able to change it.
‘He’s disappointed not to play, definitely. But, similarly, he sees some good players around.
‘So far this season it’s been Gareth Evans or Brett Pitman in the number-10 role.
‘Then we have Oli Hawkins, Omar Bogle and James.
‘They’re pushing hard to drive and bring the best out of each other. That's happening.
‘James is a very good pro and a very honest one. I can’t complain about his attitude at all but he has been frustrated.
‘Sometimes you can look right out of it but football changes. You must be ready and I’m sure James will.
‘He can score goals at this level. He is a good, experienced number nine and is someone I have a lot of time for.’
Jackett opted to replace Bogle with Hawkins at Wembley, with the change paying dividends.
He added: ‘Sunday proved you do need changes to tip a tight game in your favour.
‘We didn’t have those options last year but they can provide a key combination for the run-in.’