Tottenham manager Tim Sherwood says his side face a test of character to salvage their top-four hopes.
A 1-0 defeat at struggling Norwich on Sunday left Spurs six points behind fourth-placed Liverpool in the race for the Champions League places.
Sherwood, who took charge at White Hart Lane in December, said: "[The gap] looks big. It's a real blow to us.
"It's the first major setback I've had and we're going to need to be spirited to show we can bounce back."
Liverpool tightened their grip on the top four with a 4-3 victory over Swansea at Anfield, and Sherwood said Tottenham could not count on their rivals dropping points.
"We just have to concentrate on winning our games," he said.
"We can't rely on other people to lose all their games and us qualify for the Champions League, because that's not going to happen."
Tottenham's failure to score was their first in the league since Sherwood took over.
"I thought we were poor in the first half," he said. "We saw an improvement after half-time but they got a goal that put the winds in their sails.
"We created clear-cut chances after that, but if you don't score you don't win football matches.
"The second half was more like what we know we can do, but we are bitterly disappointed. We have to tighten up our entire performance. We've got two home games where we have to bounce back - we have to see if we have the character to do that."
The result was at least as significant for Norwich manager Chris Hughton, who was under growing pressure following comments by chief executive David McNally.
McNally had suggested the manager's job was in the balance after a run of just one win in 11 league matches but Hughton said he had not considered the prospect of being sacked.
He said: "It's not something that I thought of. There's enough that goes into a week of preparing for a game and my focus was only on this game.
"One thing I can guarantee you is that everyone is pulling in the right direction here.
"It feels like a big win. My biggest concern was we've had a good level of performance over the last few games but didn't get the results we deserved. We got that today.
"I'm pleased for the lads because they were as frustrated as anyone."