Swiss side Basel eliminated the London club on penalties on Thursday but Vertonghen is confident of shaking off the disappointment and earning UEFA Champions League football for next season.
Andre Villas-Boas' side currently sit in fifth position behind arch-rivals Arsenal and level on points with fourth-placed Chelsea, who have a game in hand.
But Belgium international Vertonghen told the club's official website: "We have to stay together and to go for that top four place in the Premier League.
"We have had a rest, we clear our heads and we come back against Manchester City.
"A lot of players could be coming back, important players and we only have big games now, City, Chelsea, all cup finals. We go for the highest place possible."
On the defeat to Basel, the 25-year-old added: "I hope it makes us stronger.
"You could see there was a team together on the pitch, we really fought for each other for 120 minutes."