Shaun Derry was adamant his side were denied a penalty as they fell to defeat to Pompey.
But the former Fratton Park midfielder reserved praise for Blues defender Christian Burgess who went up against U’s powerhouse striker Uche Ikpeazu.
There may have been plaudits for Burgess but Derry felt he brought Ikpeazu down in the box in the first half.
The U’s boss told the Cambridge News: ‘Was I the only one kind of throwing my arms around? I thought it was a penalty.
‘I thought it was a foul and it happened to be in the 18-yard box. If that had perhaps been five, 10 minutes after their goal it might have been a different kind of outcome.
‘There are going to be many of them between now and the end of the season.
‘You’re looking a little bit of consistency and perhaps, in that sense, we didn’t get it.’
Burgess and Matt Clarke earned respect from Derry, who feels Pompey possess League Two’s top players.
He said: ‘Their two centre-halves were big players.
‘I thought Uche (Ikpeazu) caused a lot of problems again and we needed to be a bit more clinical around him.
‘In terms of them handling the prowess he brings, I thought Burgess, in particular, had a good afternoon.
‘They have probably the best players in the league and we’re talking about us being really disappointed not to have got something out of the game.’
Derry took solace from the fact the Blues didn’t create a mass of chances against his side.
He added: ‘We’ve come up against a massive football club in League Two and I’m frustrated we’ve not got anything out of it.
‘People will probably question whether we had any clear-cut chances, but I felt there was one team on the front foot, especially in the second half.
‘We’ve lost at home, but we’ve lost to Portsmouth who shouldn’t be in this league in the first place.’
– JORDAN CROSS