Jose Mourinho admitted that a top-four finish in the Premier League was looking increasingly difficult as his side were beaten 2-1 at West Ham United on Sunday — their fifth defeat in their last six league games.

Tottenham conceded early in each half and although the introduction of Gareth Bale as a second-half substitute saw a massive improvement, they could not salvage anything.

The result lifted West Ham into fourth spot, nine points above ninth-placed Tottenham.

“Our potential is higher than where we are so of course there is frustration,” Mourinho said.

“We should be in a better position. To think about a top four spot is getting very difficult. To play in the Europa League will give us a window of opportunity to get a Champions League spot by winning it. Of course, difficult, but it is possible.”

Mourinho has managed 81 points in his first 50 league games for Tottenham since replacing the popular Mauricio Pochettino.

That is his lowest haul at the same stage of any of his managerial stints at Porto, Chelsea, Inter Milan, Real Madrid and Manchester United.

Asked whether he would have to re-examine his methods in the face of one of his worst spells as a manager, Mourinho said he would change “zero”.

“Mine and my coaching staff methods are second to nobody in the world,” he told reporters.

He also denied Tottenham were in crisis.

“I don’t know what you mean by crisis. If crisis is frustration and sadness in the dressing room then I believe so and I think we all showed that,” he said.

“When a team fights the way the team did in trying to get a different result it’s never a group crisis. A group crisis is when you’re not together. I say it’s a bad run of results.”

Mourinho’s decision to leave Bale on the bench looked questionable considering the impact the Welshman had in the second half after replacing Erik Lamela.

But he again said Bale could not have played 90 minutes.

“I know his quality. I believe as a coach I don’t have to speak so much about the situation but with a Gareth Bale completely fit and ready to play 90 minutes of every game of course he would (start),” Mourinho said.

“We are trying everything with him to recover him to be at a good level. To play 65 minutes like he did Thursday then today he couldn’t start the game today, he wouldn’t have 90 minutes to give us. But he is starting to be more intense.

“He was good in the second half.”