Ashley Harris has been urged to bounce back from his surprise Tranmere absence.
The youngster was not named in Guy Whittingham’s squad for last weekend’s trip to Prenton Park.
It is the first time since March he has failed to make a match-day squad when fit.
Harris, who turned 19 at the weekend, has made 17 appearances this season, the majority of those from the bench.
Yet at Tranmere the likes of Jack Compton, Scott Allan and Jake Jervis were selected ahead of him.
Both Allan and Jervis made crucial impacts from the bench as Pompey picked up an impressive point in the 2-2 draw.
Preston visit Fratton Park this weekend and Whittingham has called for a reaction from Harris.
He said: ‘Ashley not being there was down to the fact we have everyone fit and there were certain positions we wanted to utilise.
‘That does not necessarily mean he is going to miss out this weekend or any other.
‘He was disappointed and that is how it should be, you want people who actually care.
‘If he wants to put it right he has to show me in training and I am sure he will do.
‘But we also have got to be very careful with younger players like Ashley.
‘He has only just turned 19, that is what we have got to remember.
‘Everyone has been telling me he deserves to be in the first team and what a good player he is.
‘However, these young lads do go through periods when they dip and when they peak.
‘That is what happens to those in that age group.
‘We work with him day in, day out and see at close range what he is like.
‘It happened to Adam Webster a little while back but he returned from it.
‘Ever since the age of 18 Ashley has been part of the first-team squad but he is still young.
‘There is not an experienced head on those young shoulders, he is still learning.’
Harris missed the FA Cup defeat to Notts County through injury.
Other than that he has been an ever-present in Pompey’s squad this season up until last weekend.
The last time he was not included when fit was the 2-0 defeat at Brighton on March 10.
However, by that stage he had yet to make his first-team debut.
Now the Purbrook youngster is pushing to reclaim his squad spot when the Lilywhites come to Fratton Park on Saturday.
‘Ashley has responded well and trained hard this week as usual,’ added caretaker boss Whittingham.
‘We’ll have a look at the team again this game and see how we want to play.
‘At the moment we have a few options, especially with the injuries clearing up.
‘Someone like Jack (Compton) gives us something different.’