Ronan Curtis has shrugged off suggestions tiredness is hampering his Pompey displays.
Instead the Irishman has pinpointed a dip in confidence as impacting upon late-season form.
Pompey’s young player of the season has amassed 49 appearances during an impressive maiden Football League campaign.
Yet performances have tailed off, while the last of his 12 goals arrived in the televised 2-1 defeat at Charlton in early-March.
It has been a gruelling past 18-months for Curtis, who was recruited from League of Ireland side Derry City last summer.
The winger has been given two weeks off since January 2018 – an exhausting schedule for the 23-year-old.
But he is adamant that workload is not behind his search to recapture that early-season form.
Curtis said: ‘When you think about it, I’ve played since January last year, internationals as well, so I’ll probably only have two weeks off this year as well.
‘I still give 110 per cent, whatever club I’m at I give 110 per cent, that’s my work ethic, I work hard for my team-mates.
‘But it doesn’t feel like it is affecting me, I’m a fit lad, I’m young, I can do it, as I have done all season.
‘It’s nothing to do with tiredness, it’s a lack of confidence really, that’s what I think it is.
‘When you are coming off at 56 minutes or 65 minutes in a game, that doesn’t do your confidence good. So I would say it’s down to confidence.
‘Every player dips in confidence. We are not all like Ronaldo and Messi, we can’t keep the form up for every game of the season.
‘Every player is affected by confidence. It is confidence that makes you drive on.’
Should Curtis feature in Thursday’s play-off semi-final second leg, it would represent a 50th appearance this season.
A total of six players have already reached that figure – Matt Clarke (59), Gareth Evans (55), Jamal Lowe (55), Craig MacGillivray (53), Tom Naylor (52) and Lee Brown (50).
And Sunderland marks a club-record 62nd game this term.
Curtis added: ‘Of course you get tired, if we go the whole way in the play-offs, we get all of June off and then it’s back in for pre-season.
‘If you ask any of our lads or anyone around the country who isn’t in the play-offs, would they rather be on holiday then trying to go up into the Championship, they would tell you the play-offs.
‘That’s what we do, that’s our nature, that’s our work, that’s our job.’