Reds players had been out together to watch the match, and they celebrated long into the night following the confirmation of the club's first title in 30 years.
But Lonergan says they were fully switched on in training the next day.
“There was a five-a-side game going on and a decision was given which someone wasn't happy about.
“It led to a lot of shouting – not fisticuffs or anything – because players wanted to win that five-a-side game.
“Forget the fact we had won the title the night before, the intense focus was on this game in training.
“That summed up the attitude about Liverpool, it was full of winners."