Mauricio Pochettino says it could take between five and 10 years for Tottenham to develop the mentality to legitimately push for the Premier League title.
After the loss, Pochettino admitted that the defeat likely ended the club's title hopes this season.
And now the manager says that it could take an even longer time to develop the mental strength to truly compete with the elite.
"If you want to be a real contender, playing well or not, it's (the game against Burnley) a must-win," Pochettino said.
"You need to show you are fighting for big things and I am frustrated because we didn't show the same energy as Burnley, the same attitude as Burnley, the same ambition as Burnley.
"We have to look at ourselves and maybe assess ourselves in different ways - we are not looking for excuses.
"It is holding us back and it might take five years' work, 10 years' work to change that."
Tottenham is set to face Chelsea on Wednesday as the Blues look to rebound from Sunday's Carabao Cup final loss to Manchester City, a match headlined by Kepa Arrizabalaga's refusal to come out in extra time.
Chelsea are sure to be extra motivated for the match, and Pochettino insists that his side will also bring the right mentality to Wednesday's clash.
"To go away and play the likes of Chelsea, Arsenal - that is easy," Pochettino added. "You don't need a manager to motivate you for those games, that is normal.
"But if we don't have the will to show that (against Burnley), then you don't deserve anything.
"What we showed on Saturday was that we are a good team, have good quality but not enough to win a Premier League title - that is the reality.
"If you are not able to beat Burnley it is impossible to think you will win the title - if you do it's because others have lost the opportunity themselves.
"The reality is that it will be tough to win the Premier League because of us, not because Liverpool or Manchester City are any better."