Ben Close feels his side have to be satisfied with a Doncaster point.
Pompey couldn't equal a club-record five opening league wins after the 0-0 draw at the Keepmoat Stadium.
Kenny Jackett's men came under first-half pressure but had chances to win it after the break.
Then midfielder Ben Whiteman had to go in goal, after keeper Marko Marosi was sent off with all three subs used.
There was a hint of frustration Pompey couldn't make more of that opportunity, but Close felt a draw was satisfying.
He said: 'Overall looking at the game a clean sheet and a point is a good return.
'But we had some good spells after the break and they were down to 10 men at the end, so there's a hint of disappointment around.
'It's in our nature to want to go out and win games, but taking a step back and looking at it it's a good point.'