Mahlon Romeo lamented Pompey’s fortunes at either end of the pitch at the Stadium of Light.
They were beaten 1-0 by high-flying Sunderland on Wearside, with Elliot Embleton stealing possession to net the only goal just before the interval.
But the visitors had dominated up until that point, controlling possession without creating many clear-cut openings.
And Romeo knows the Blues have to put that right quickly if they are to get their season back on track.
The loanee said: “It’s been a recurring theme of our performances this season – we started well, deserved more and then gifted our opponents a goal.
“That’s something that has happened perhaps too many times, so it’s definitely an area we need to work on.
"Anyone who was there watching the match can see that we should have been ahead by at least one goal."
“So we had to shake that off and then look to score ourselves, but I don’t think we really did enough in the final third.
“Anyone who was there watching the match can see that we should have been ahead by at least one goal.
“But that’s not how football works and sometimes teams will score against the run of play, so it’s about how we respond.”
Pompey have netted once in their past four league games, but Romeo believes their new arrival will soon start firing.
He said: “Tyler (Walker) has just come in and he’s an exciting player. Once he gets going, then I’m sure he’ll be flying.
“He’ll feel like he’s had his grace period now with two games and I’m looking forward to seeing what he’s capable of.”