The Italian rejected any focus on refereeing controversies and instead framing Sunday's home game against Everton as the most important match in the club's recent history.
Goals from Enzo Fernández and Andrey Santos gave Chelsea a comfortable lead before Richarlison's late backheel pulled one back, but it was not enough. Spurs are now 17th, two points above the relegation zone, heading into the final day.
De Zerbi, who took charge of the club in April, was asked about a penalty appeal late in the game when Micky van de Ven was pulled down in the box with the referee waving play on. He refused to engage.
"It's not my business now. My focus is to prepare the next game and to make points. Because Sunday is the final for Tottenham — not Bilbao against Manchester United. The most important game is Sunday. Because last season they played for the trophy, now we play for something more important than the trophy."
He elaborated on what he meant by that distinction, producing the most striking moment of a long press conference.
"The pride, the history of the club, the dignity are more important than the trophy. The trophy you can win, you can lose, nothing changes in your life. You can have one trophy more, but the most important thing is to keep the dignity, to keep the pride, to go on holiday like this — and he raised his head — not like this — and he looked at the floor."
De Zerbi was also asked about the performance itself. He acknowledged that Spurs had missed an early chance when Mathys Tel's header hit the post, and that Fernández's opener was a goal of real quality that was difficult to defend.
"I think we played a good game. We could score at the beginning of the game with Mathys Tel. We conceded a goal — a great goal from Enzo Fernández — but I think we could do something better especially in the second ball, in the long ball, with Udogie. And before the second goal we could score with Richarlison."
He pointed to the final 20 minutes as evidence of what this squad is capable of when it believes in itself.
"I would like it if we play Sunday like the last 20 minutes, because in the last 20 minutes we showed more energy, more passion, something more inside of us. But it's difficult. It's an opportunity for every one of us, because through this period, these games, these days, we can become better as a coach, as a player."
He addressed the question of whether the players truly understand what is at stake.
"Very well."
When asked how he knows, he was direct.
"Because I'm living just for Tottenham. I have lived the last 45 days just for one thing. I know them very well. Every one of them is focused on the target. They are working hard during the week and every one of us wants to achieve the goal."
He also confirmed that James Maddison, who came off the bench and went close to an equaliser before being denied by Jorrel Hato's perfectly timed tackle, is unlikely to start — though De Zerbi believes the result can be achieved regardless.
"James Maddison can't play more than 20 or 25 minutes. I have a medical staff behind me, I am not a doctor, I am not a physical coach and I have to follow what they say. But I think we can stay up with James and without James."
He ended with a tribute to the Spurs supporters who had made the journey to Stamford Bridge.
"The fans today have been fantastic, fantastic and we have to say thanks because they were incredible."