Tottenham Hotspur have shown big improvements in their game over recent months.
Spurs take on Sheffield United in the League Cup tonight and Vertonghen admits that confidence is high in the camp.
Although the Lilywhites will have to guard against complacency, the Belgian international is full of belief and that optimism is matched by his teammates.
“The mentality is good," he said. "We’ve done well in the last couple of months. Okay, we lost against Palace and Leicester City but everyone believes we can achieve something this season.”
Spurs have indeed improved over the recent months of the campaign and they will head into tonight's match as heavy favourites.
Mauricio Pochettino's men have a 1-0 lead to defend after Andros Towsend's penalty in the first-leg gave them the victory and it would be a huge shock if Sheffield United were able to turn around the deficit.
The League One club have made a habit of beating Premier League sides in cup competitions, but beating Spurs would surely be their greatest achievement yet.
Whoever does win the tonight's tie will face Chelsea in the final, meaning that their hard work is not done.
The Blues overcame Liverpool in extra-time yesterday evening and it sets up an intriguing clash at Wembley.
If Spurs do get there, as expected, they will be confident of being able to beat Jose Mourinho's men after their 5-3 win against them earlier in the season.