Mauricio Pochettino accepts Tottenham still have much to learn if they are to become a force in the Premier League.
Spurs mounted a sustained challenge for the title this season, but a three-match winless run saw their chances slip away.
Sunday's 2-1 defeat at the hands of Southampton came after they threw away a two-goal lead to draw 2-2 at Chelsea last Monday - a result that confirmed Leicester City as champions.
Pochettino saw his side waste a host of chances against his former employees in their final game at White Hart Lane this season, and the Argentine admits there is work to do to build on their strong showing this term.
"The first half we played very well, and we had more than 70 per cent possession," he said.
"But we needed to be more solid and show more consistency - we lacked this today. I'm disappointed but we're still fighting.
"There was no hangover from last week - we started the game very well. They had few shots and scored two goals, but this is football and I congratulate Southampton.
"We still need to learn a lot of things - we need to keep improving into next season. It's important to finish second, and to do that we need to win games.
"The last few weeks have been tough, [but] we are still in a great position and if we look back to the start of the season we all should be proud. We need to look at ourselves, not at our neighbour.
"We need to think like a big club, not worrying about what's happening in another house. We need to change that mentality, to be strong, to be a big club."