Kenny Jackett rued the costly moments which sent Pompey to defeat against his old side Rotherham.
The Blues fell to a 1-0 loss against the Millers in front of the Sky Sports cameras and a crowd of 17,118 at Fratton Park.
Jackett felt two big chances either side of half-time from Jamal Lowe were key.
And the Pompey manager believes there was a strong penalty appeal not given after Michael Ihiekwe caught Ollie Hawkins with a boot to the head.
Jackett said: ‘We had two good chances either side of half-time from Jamal Lowe.
‘That happens but he’s been a good player for us this season and has to go and get his next goal.
‘They were two big chances and I felt we had a good penalty appeal not given.
‘Outside the box there’s no doubt it would have been given. His foot was high.
‘It was a tight game. We didn’t take our chances or get the rub of the green on a big decision.
‘The second-half performance was a lot better than the first, though, I’ll admit that.’