The Sunderland winger has admitted he’s been playing through the pain barrier in his side’s push for League One automatic promotion.
McGeady has been the Black Cats’ talisman this term.
He’s netted 11 goals and was named in the PFA League One Team of the Year, alongside the Blues’ Jamal Lowe and Matt Clarke, on Wednesday.
Sunderland trail third-placed Pompey by two points heading into Saturday’s Stadium of Light showdown.
Both clubs have designs on leapfrogging second-placed Barnsley with three games remaining.
McGeady revealed he fractured a bone in his foot in the Black Cats’ 3-0 win at Accrington earlier this month.
That’s meant the he’s been injected with anaesthetic during his past three appearances.
And McGeady conceded he hasn’t felt himself in periods of those games.
The Republic of Ireland international told Chronicle Live: ‘It's probably not the right thing to say because if you put it out in the open that you have an injury, teams might try to capitalise on it and take advantage.
‘Against Accrington I fractured a bone in my foot, so either my season was over or I tried to manage to play with the aid of anaesthetic injections to try to ease the pain.
‘So from day to day I have been doing nothing, not training, and then playing.
‘That's what has happened in the last two games.
‘If I am being totally honest, in parts of those games I don't feel myself because there is that thing in the back of my head where I still have this pain.
‘But the manager wants to take the risk and I do as well because I didn't want my season to finish because I was enjoying playing and I am enjoying my football and the team was on a good run.
‘I didn't want my season to finish six weeks early.
‘So myself, the management, and the physios, took the approach that I could play and not make the injury any worse by getting injections before the games.
‘I think the manager sees me as, not a luxury player, but someone who can change things.
‘That has been the thread through my whole career and the manager is okay with me lacking in other parts of my game because of the injury.
‘If I am able to produce something that helps us get to closer to our goal this season, he will accept that.’
Pompey have defeated Sunderland twice already this season.
Kenny Jackett’s men delivered a 3-1 win at Fratton Park in December, before triumphing in the Checkatrade Trophy final at Wembley last month.