But the Liverpool midfielder insisted he would not beat himself up from now until May wondering whether it costs them Champions League football.
Lallana fluffed his chance to secure the win over Manchester City with eight minutes on the clock, seven yards out and with goal at his mercy.
But he said: “I’m only disappointed not to score it because it could have been the difference on the day.
“They happen sometimes. My eyes lit up and I just thought to myself if I get some connection on this, it’s a goal. Then it just took a bounce in front of me.
“I might have taken my eyes off the ball for a second and got excited. I’m absolutely gutted as it could have proven to be the winner. It was a big moment in the game and I’m so disappointed with it.”
Lallana admitted he apologised to his team-mates when he got back into the dressing room.
The draw left Liverpool unmoved in fourth place, one point behind Manchester City in third and four points clear of Manchester United in fifth.
But Jose Mourinho’s United have two games in hand of Liverpool which could see move ahead of them into the fourth Champions League spot.
For all the disappointment about Lallana’s miss, Liverpool’s draw with City continued their unbeaten run against fellow top-six sides.
However Lallana admitted it is the form against some of the teams from the lower rungs of the Premier League table which needs improving.
“You would rather the problem this way around rather than struggling to get points against the top teams,” he said.
“But I’m sure it will be easier to correct and get points against the teams who are scrapping against relegation in the future.
“We know we need to work on that and our record against them needs to be better. We will continue to do that.”