The 27-year-old had been one of the first names on the team sheet ever since arriving from Ajax in 2012, yet has found it hard to pin down a regular first-team berth this term.
Vertonghen's place on the bench in Saturday's 4-1 defeat at Manchester City reignited rumours that all may not be well between the defender and Pochettino - something both have downplayed in recent weeks.
Pochettino attempted to extinguish that speculation once again on Wednesday, saying: "Jan is an important player for Tottenham and for us
"But a lot of rumours and information and different situations, and for me it's easy because I don't read it
Never.
"I know the players are sometimes affected by comment or rumours and they call me about the rumours but Jan is a very important player for Tottenham and for me.
"After the Arsenal and Southampton games, we had the international break
Younes Kaboul and Federico Fazio worked very hard here [during that] and are fresh
I gave them the opportunity to play but I haven't changed my view on Jan
For me, he is a very good player and he is a key player for us."
Vertonghen recently revealed talks over a new, long-term contract had come to an end, although Pochettino denied that had upset the defender, so too the fact he was overlooked for the captaincy.
"I never hear from Jan that he wants to leave or change something," the former Argentina defender said.
"After it is impossible to hear or to trust in other people around him because for me it is important when we have a chat inside my office that never Jan told me he wants to leave the club.
"I have trust in my player and Jan never told me about that
He is happy at Tottenham
Maybe sometimes he wants to play more but my decision is to take a decision
He is happy and I'm happy with him."
Vertonghen came off the bench at the Etihad Stadium after Fazio was sent off in Spurs' latest heavy defeat to City.
Pochettino says the players have responded well to that 4-1 loss but is well aware a winning response is needed in Thursday's Europa League clash against Asteras Tripolis.
The Greek side arrive in north London as a relatively-unknown quantity but Spurs' coaching staff have done their homework on the current Group C leaders.
"I have a lot of information about Asteras," Pochettino said
"It is a very good team, a lot of Argentine players, seven, and I believe that they have a very good philosophy.
"They have very good players and had very good results against Partizan and Besiktas.
"They are a very dynamic team, play well, offensive, brave and we expect a very tough game."
Source : PA
Source: PA