Andy Awford is adamant Lawson D’Ath should have seen red as Pompey were eliminated from the Johnstone’s Paint Trophy.
The Northampton midfielder was booked following an ugly challenge on Ricky Holmes in last night’s 2-1 defeat for the Blues.
The incident sparked angry scenes instigated by the Pompey dug out, with referee Graham Horwood electing to issue a yellow card rather than sending D’Ath off.
Awford later studied video footage before speaking to the match officials and then the waiting media.
And he was insistent Chris Wilder’s men should have been reduced to 10 following the tackle.
He said: ‘There are three incidents that the referee and his officials haven’t picked up.
‘It was a straight red, no doubt about it.
‘I don’t think Lawson is a horrible player or mean to hurt anyone - I am not saying that for one minute - but it was late, it is high and it is a red card, it’s as simple as that.
‘They were struggling to hang on with 11 at the end when we were banging on the door and couldn’t quite get there for the equaliser.
‘I thought we played really well in the first half, we had five kids out there who have all come through the Academy and I thought all five of them were magnificent.’