Steve Cotterill has ruled out Pompey’s young guns pushing for a spot in his first-team squad.
Ryan Williams and Sam Magri both made their senior debuts in the opening pre-season friendly at the Hawks on Monday night.
Australian Williams caught the eye with an impressive 25-minute cameo on the right flank.
That was halted when the Academy prospect picked up a tight calf and was substituted in the second half.
England under-17 defender Sam Magri also made an appearance, coming on as a 78th minute substitute.
Both players have been progressing well in youth football, overseen by Academy manager Andy Awford.
But Cotterill does not yet believe the time is right to give them regular involvement in the senior set-up.
He said: ‘I don’t think we will be seeing them in the first-team squad regularly at the moment. They are far too young, really.
‘We are talking about them being 17 years of age, they are not physically developed, they are far from being men.
‘They are good young boys who have done a bit of training with us so far – and will continue to do that.
‘But there is a fair bit of physical development needed by a couple of our younger lads.’
Other youngsters involved on Monday night were Lewis Stockford and Lewis Tallack.
Stockford, a midfielder from Southsea, started the match, while defender Tallack, from Waterlooville was a substitute.
Both are first-year professionals who have climbed the Blues’ ranks.
Cotterill must now decide whether to include any of the youngsters in his squad jetting out to America on Sunday.
He added: ‘I don’t know if any of the four young lads will go to America.
‘If they do then there maybe only one or two. Maybe.
‘That depends on what sort of business we do in the transfer market this week.’