Frustrated Michael O'Neill labelled Northern Ireland's scoreless draw with Holland as a "missed opportunity".
Captain Steven Davis squandered a first-half penalty as O'Neill's side missed out on a famous victory over the Dutch.
The Rangers midfielder blasted his 32nd-minute spot-kick over the bar after Dutch defender Joel Veltman was adjudged to have handled inside the box.
"It it a missed opportunity," O'Neill said.
"First half we started the game with great purpose and had chances. We maybe needed that bit of good fortune, the one Corry Evans had blocked, things like that.
"The penalty was a good chance and it maybe took the wind out of our sails. We couldn't get any momentum in the second half. And that is down to the quality of the opposition as well."
O'Neill said he felt for Davis, who was making his 116th appearance for Northern Ireland to become the most capped UK midfielder.
"I feel for Steven. Of course I do," O'Neill said.
"It was a big moment for him. You can sense his disappointment. But it shows his character trying to drive the team on.
"It's not easy at 35 in the middle of pitch playing against players much younger."
O'Neill also hit out at the delay leading up to Davis' penalty after Holland goalkeeper Jasper Cillessen came off his line to question the positioning of the ball.
There was a three-minute gap between referee Szymon Marciniak awarding the penalty and Davis taking it.
"That was poor. I think that could have been handled better by referee," he added.
Northern Ireland will now go into next year's playoffs, with the draw to be made on November 22.
"It is an achievement reaching the playoffs, especially when you look at our group," O'Neill added.
"Germany and Holland will qualify and Belarus are in the playoffs, and so are we.
"The good thing is the opposition in the playoffs won't be the standard of Germany and Holland."
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