Jamie Redknapp accused Tottenham of being arrogant after they were dumped out of the Carabao Cup by West Ham.
Spurs looked on course to reach the quarter-finals of the League Cup after goals from Moussa Sissoko and Dele Alli gave them a healthy half-time lead.
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But the Hammers produced a stirring second-half fightback as Andre Ayew's double and Angelo Ogbonna's winner eased the pressure on manager Slaven Bilic.
Asked if Spurs had been complacent, Redknapp told Sky Sports: "I'd go as far as to there was too much arrogance from Tottenham.
"They got all the plaudits, and rightfully so, after Sunday - they were fantastic and outworked Liverpool in every department.
"But today's performance was a shocker. To go from being two goals up and completely in control to losing the game showed signed of arrogance and complacency.
"I was pleased Mauricio Pochettino didn't try and style it out because they were poor in the second half."
Wednesday's performance was of stark contrast to Spurs' previous two games, which saw them draw at Real Madrid and demolish Liverpool at Wembley on Sunday.
Redknapp acknowledged that Spurs' progress in the Premier League, Champions League and FA Cup held more significance than the Carabao Cup, but Redknapp believes it was an opportunity missed for Pochettino's men.
"With the players he has got, it won't be long until he's judged on what he's won," the former Spurs midfielder added.
"If you don't win things with the players you've got it won't be long until you come in for criticism.
"Tottenham are one of the best clubs around at the moment but that second-half performance was not up to scratch.
"You could say that this competition is the last of Pochettino's priorities but it's not, this is a great marker to put down.
"With a trophy in the bank, it could have provided a feel-good factor for the rest of the season to go on and win more."