Paul McCallum has pledged to repay Andy Awford for standing by him.
The 21-year-old striker has endured a troubled start to his Pompey career after being given a seven-match ban.
The West Ham loanee’s dismissal for violent conduct against Southend in January was punished further by a charge of improper conduct.
McCallum’s spell on the sidelines then coincided with a torn groin picked up in a Blues reserve friendly at Woking.
Now he is back in the first-team frame, having climbed off the bench in the last two matches.
The forward also netted a hat-trick in the reserves’ 3-1 victory over Leyton Orient on Tuesday.
And he is keen to make an impact for Blues boss Awford as he bids to make up for wasted time.
McCallum said: ‘It has been a frustrating time for me, but it’s great to now start getting some minutes under my belt to make sure I am fit when called upon for the first team.
‘I tore my groin against Woking during my time out which stopped me from training and I had to go back to West Ham to receive treatment.
‘That kept me out of the seven games I was suspended for.
‘So it was the chance to heal and reflect.
‘It made me realise I cannot do something stupid like that because it could affect my career.
‘My contract is up in the summer and it could have been a silly mistake which cost me.
‘It happened in the heat of the moment, we were losing 2-1 and I have been stopped running forward, it has upset me and I have reacted silly.
‘Then I couldn’t believe I had been sent off and reacted silly again.
‘I realised what I had done and apologised straight away. It was wrong of me.
‘But the gaffer has shown faith in me and hopefully I can repay him.
‘I have learnt from it and we will move on now.
‘The only thing I can do is score goals and make the gaffer realise he has a goalscorer at the club and start me.
‘I got 25 minutes against AFC Wimbledon and obviously I don’t want to be coming off the bench.
‘I want to start matches so have to keep grafting away in training and make sure I am ready to play.’
McCallum took his reserve-team tally to four goals in two league games during an impressive display against Orient.
It was a timely goal haul in front of the watching Awford.
And with eight first-team fixtures remaining, he is also eyeing a contribution in League Two.
He added: ‘I did a couple of sessions at West Ham when I was fit and then came back down to Pompey and started training a couple of weeks ago. Now I’m ready to play.
‘Hopefully Tuesday shows I will score if given the chance – and I am very confident in myself that in upcoming games I will.’