Mauricio Pochettino urged his side to forget about Saturday's 1-0 home defeat to West Ham United in the Premier League when they face Ajax in Tuesday's Champions League semifinal first leg.
Spurs suffered an unexpected setback in their final match ahead of a clash which is being billed as their most important in more than half a century.
Saturday's loss was their first in their news stadium but Spurs struggled to assert themselves against dangerous opponents who always threatened on the counterattack.
"We have to forget about it, move on and think about Tuesday,"Pochettino said. "It is tough to prepare for a semifinal against a very good team like Ajax."
Pochettino, who made four changes from the midweek win over Brighton, declined to offer an update on the fitness of Moussa Sissoko and Harry Winks, who are both struggling for fitness, and said: "They will be assessed."
With Harry Kane, Serge Aurier and Erik Lamela definitely out and Son Heung-min, who scored three goals against Manchester City in the two Champions League quarterfinal legs, suspended for the first leg, Pochettino must decide whether to switch Lucas Moura to a central striker role or give a start to Fernando Llorente.
Spurs' future remains tantalisingly poised between possible European glory and failure to even qualify for next season's tournament. Saturday's defeat means any two of Chelsea, Arsenal and Manchester United could yet deny them a top-four place although their fate remains in their own hands.
"It is a fight, it is a race, with two games to play," Pochettino said. "We knew that before.
"I think we did not manage the ball properly. It was a difficult game but in the second half we conceded a lot of space for them to counter attack. But we need to look forward. We cannot stop to think about what we did not do today."
"I think Marko Arnautovic was very good," Pellegrini said. "He made a brilliant pass for Antonio's goal.
"It has been a difficult season but I am sure that we will recover the player that he could be. This is a transition season we try not to change too much in our team.
"We have demonstrated in big games that we can do it but we must mentally convince ourselves that we can do better."