London - Tottenham Hotspur manager Mauricio Pochettino said his side are now in must-win mode after their loss to Bayer 04 Leverkusen in the Champions League.
"We must win in Monaco," Pochettino told reporters after their 1-0 defeat at Wembley. "If not, forget the Champions League."
With two group games to go, Pochettino called on his players to step up.
"We need to improve and we don’t have too much time," he said. "We need to be critical and put ourselves in front of the mirror and say: 'Come on we need to improve.'
"To find the answer is inside us and that is very important."
The Argentine made a point of declaring the venue was not a factor.
"We were poor today and in both games at Wembley, we didn’t show our real quality."
Pochettino expressed his displeasure after Tottenham lost their opening game against AS Monaco at Wembley in September.
He suggested ahead of the Leverkusen match that visiting teams would get a boost from playing at England’s national stadium.
"There is no better place to play than Wembley. Losing in front of 85 000 people, it’s embarrassing for me, it’s a shame. We have to look at ourselves."
He said the White Hart Lane versus Wembley issue was not a factor.
"You cannot blame Wembley. Wembley for me was fantastic, but we need to show more. We were poor again, we need to find answers in ourselves. We need to be critical. We were the problem, not Wembley.
"We were very disappointed we didn’t show quality. Stop blaming Wembley, it’s not Wembley.
Spurs have been struggling without Harry Kane and Toby Aldeweireld, who have been out injured. Kane has been off the pitch for eight weeks with an ankle injury, while Aldeweireld has been out for three weeks with a knee issue.
Kane returned to full training this week, although it was not known whether he would play against Arsenal at the weekend.
This is the second loss at the famous English stadium that Spurs have suffered after losing their opening Champions League game to Monaco.
The two matches served as a dress rehearsal for next season when all of Spurs' games will be held at Wembley Stadium while their new White Heart Lane stadium is developed.