Suarez has scored 28 goals in 25 appearances this season to help the Reds to their current position of second in the Premier League table, four points adrift of leaders Chelsea, with a game in hand.
Spurs had their own title ambitions at the start of the campaign, but a difficult year in which they have sacked their manager and been on the end of some heavy defeats means that they are way off the pace.
The North London outfit are nine points behind Liverpool, but Vertonghen feels that there is not much between the teams, who meet at Anfield on Sunday, except for the brilliance of his former Ajax teammate.
"Suarez," he told reporters. "Suarez is the reason for that. At the moment he is up there as one of the best strikers in the world. I think he is the difference between the teams.
"[Daniel] Sturridge obviously is doing well and those two are very hard to stop. They are one of the best teams in the league and they show it every week.
"It is going to be very hard, especially at Anfield, and I hope we can play as we did last season because we did very well, not the result but the performance."