MAURICIO Pochettino says he will know within 50 seconds whether Tottenham can pull off a comeback against Gent on Thursday.
Spurs host Gent at Wembley in the Europa League looking to overturn a 1-0 deficit from their dismal display in the first leg in Belgium last week.
A 3-0 thrashing of Fulham in the FA Cup on Sunday saw Tottenham back at full pelt, but inconsistency has been a regular feature of their form in recent weeks.
They have won three out of their last seven in all competitions and Pochettino believes his side often set the tone at the start.
"When we start a game, if you only watch 50 seconds, you don't need to be a genius to know we may struggle and have some problems in that game," Pochettino said.
"In that moment it's too difficult to change. We changed the formation at half-time to try and lift them but it was impossible.
"The problem is when you start not in a good way, it's too difficult to change that perception and then you give a very good signal to the opponent that you are not focused on the game.
"You need to change that mentality."
Crashing out of the Europa League would come as a bigger blow to Spurs than in previous seasons, given they have a genuine chance of winning the competition and appear unlikely to catch Chelsea in the Premier League.
Spurs have not won a European trophy since 1984 - or any silverware since lifting the League Cup in 2008 - but Pochettino says there is no shortcut for a club of Tottenham's financial muscle.
"We cannot buy time, that is the most important thing for us," Pochettino said.
"You never know in football, but in a short period you cannot do it - only if you have money enough to buy the best players in the world. Then you maybe don't need much time.
"But the process we are in, and with our philosophy, we need time. We are showing a good basis but now it's time to develop the winning mentality."
They must also find a winning mentality at Wembley, where two home defeats all-but ended their hopes of reaching the Champions League knockout stages.
The stadium is sold out for Thursday's game and Harry Kane believes the atmosphere under the famous arch is even better than at White Hart Lane.
"White Hart Lane is obviously a lot smaller and the crowd are on top of you. We have a great atmosphere there," Kane said.
"But at Wembley it is even better to be honest with you. Even though the fans are not as close to the pitch, having 90,000 there is incredible.
"I think it's a full house again so hopefully we can use it to our advantage."
Tottenham youngsters Marcus Edwards and Kyle Walker-Peters both trained with the first team on Wednesday although Pochettino is not expected to make many changes.
Erik Lamela has begun running again as he continues his recovery from a hip problem but the club said Danny Rose remains "a number of weeks away from full training".
It places in doubt the full-back's availability for England's friendly against Germany, which is four weeks away.
"I hope he will be good for that but I cannot say anything more," Pochettino said. "We don't know. It's too difficult to say."
Gent manager Hein Vanhaezebrouck is confident his team will offer another stern test.
"I didn't think Tottenham underestimated us in the first game and they won't underestimate us either tomorrow," Vanhaezebrouck said.
"We'll try to play our game as usual and I'm confident we'll show something in this fantastic stadium."
