The England international squandered a glorious opportunity to win the game for Liverpool when he inexplicably missed the ball under no pressure and with the goal gaping after good work between Roberto Firmino and Georginio Wijnaldum.
Lallana offered his apologies to his teammates after the match, but Klopp insists that they were not needed and hailed the 28-year-old as one of the most technically-gifted players he has ever worked with.
"He's one of the best if not the best player technically I ever worked with. If he can't [explain the miss] - I thought it was because he worked so hard before," he told reporters.
"After the game Adam said immediately to me 'sorry', and I thought, 'Why?' Now I know why he thought he had to say sorry but he doesn't have to because his performance was outstanding. Everybody around me was so excited - not in the dressing room, they felt a little bit like I did - but the wonderful piece of football we did and then Adam couldn't finish.
"But of course I know Aguero could have scored once or twice, a lot of penalty situations in the game. I cannot change it. But the game is positive of course, it's how you have to play against good sides. It was intense, we defended well. The problem is I expect things like this from us and I cannot run around after a draw against Man City. But of course it's good if you get a point in a game like this."
The draw leaves Liverpool four points clear of fourth-placed Manchester United, albeit having played two games more than their fierce rivals.