Kenny Jackett aired his frustration at the ineffective changes which paved the way for defeat to Blackpool.
The Pompey boss opted to utilise Gareth Evans in a holding midfield role in Saturday’s 1-0 defeat to the Seasiders, with Andre Green coming into the side in an attacking position.
It was a move which failed to have the desired impact as the Blues laboured and offered little in the way of cutting edge for the vast majority of the game.
Jackett acknowledged that was the case.
He said: ‘Gareth came into that role at Southend and played very well.
‘And Andre came on in the 10 position at Norwich and had a very good 35 minutes.
‘So it was a continuation of the last two games, but I did feel they had more bite in midfield.
‘Andre couldn’t quite get on the ball and got closed down when he did.
‘He wasn’t able to get into good positions.
‘Putting him into those positions was what he was on the pitch for.
‘But it was a frustrating day because a very good Blackpool defence negated him.’
Jackett refused to see the defeat as a missed opportunity to put a stranglehold on the title race, with promotion rivals Sunderland and Luton drawing with each other.
He added: ‘You are always looking at the bigger picture, so I don’t necessarily (see it as a missed opportunity).
‘I just concentrate on each game.
‘Winning games in this league is hard and we’ve won many games.
‘We’ve won very few easily and we have got the details right.
‘They got the key one this time when my left-back has over-covered and Long produced an excellent finish.
‘This season we’ve got those details right but it’s a very competitive league.’