Tottenham hero Jermaine Jenas says the supposed progress under Jose Mourinho was 'all a lie'.
Spurs had won three games entering Sunday's derby against Arsenal.
But they were thoroughly disappointing in a 2-1 loss at the Emirates.
Writing for the BBC, Jenas said: "After the way things had been progressing for Jose Mourinho's side in recent weeks, what I saw from them in their 2-1 defeat at Emirates Stadium felt like a massive backward step in a number of ways.
"Spurs had gone into the game on the back of three successive Premier League wins and a couple of convincing victories in Europe, scoring lots of goals and taking a few of those teams apart.
"It was all looking good. They have got the Carabao Cup final to look forward to, they have got one foot in the quarter-finals of the Europa League and they are in touching distance of the top four. Potentially, with the way they had started playing, I had thought this season could be unbelievable.
Then, one performance later, I am left thinking that, no, it was all a lie.
"It feels like all of my optimism was completely misplaced because it came after they had played three minnows, basically, in Burnley, Fulham and Crystal Palace. The minute they have come up against anyone decent, they have reverted to type.
"That means sitting deep and being cautious, which again got Spurs nowhere on Sunday. And what we saw against Arsenal is what is going to happen every time unless Mourinho gets them back playing on the front foot."