Gareth Evans paid tribute to the member of the Fratton faithful who died during Saturday’s friendly with Bournemouth.
A man was taken ill in the Milton end around half-time, with medical staff swiftly coming to his assistance.
After receiving CPR, he was taken to Queen Alexandra Hospital, where efforts to revive him failed.
The second half of Pompey’s match was delayed while the supporter was attended to in the Milton end, with players sent back to the dressing room.
However, following consultation between referee Andy Davies, Blues chief executive Mark Catlin and managers Kenny Jackett and Eddie Howe, the game eventually resumed.
The fixture finished 2-1 in the Cherries’ favour, marking Pompey’s maiden pre-season defeat.
And afterwards, Blues vice-captain Evans spoke of his sorrow at news of the supporter’s death.
He said: ‘My thoughts are with the man’s family, it’s awful.
‘We came out to play in the second half and the gaffer started waving players off.
‘I thought “what’s going on here?”. And then I looked into the corner.
‘Someone getting CPR is not a sight you want to see.
‘Some things are more important than football and quite a few of the lads in the changing room were prepared for the game to be stopped, to be honest.
‘The man only came to watch a game of football and then something like that happened. It’s not what you expect.’
A crowd of 7,182 saw Lys Mousset net early on for the visitors before Conor Chaplin levelled on 52 minutes.
The Cherries’ Benik Afobe grabbed the winner on 54 minutes.