Spurs were booed off the pitch last Sunday after suffering their fourth home defeat in six league games against Stoke City, a result which left them 12th in the Premier League table.
The Belgian centre-back has struggled for form and fitness this season, starting just six of 11 league games under Mauricio Pochettino.
New signing Federico Fazio was chosen to partner captain Younes Kaboul at the heart of Spurs' defence in the defeat to Stoke.
Vertonghen is expected to play prominent role in Belgium's key Euro 2016 qualifier with Wales in Brussels on Sunday and will then turn his attention to helping Spurs climb the table.
The 27-year-old admitted Spurs' form so far has been nowhere near good enough but he is confident the team can turn their season around.
"It's not good enough, but we are working hard to get to where we want to be," Vertonghen said. "We want to be in the top four. We are looking for our best form.
"At the start of the season there where seven or eight teams wanting (to finish) top four, and two or three will be disappointed. I hope it's not us. I am confident we can finish in the top four.
"After this week we need to talk. Belief is still there. Hopefully we can be honest with each other, and turn things around."