Spurs agonisingly missed out on Champions League football for next season after Chelsea won the final in Munich, meaning Harry Redknapp's side will compete in the Europa League next term.
But Walker is aiming even higher than a top-four finish and reckons Tottenham have the players within the squad to mount a title challenge.
"I think it's vital [we keep them]," said Walker at an event to promote Call of Duty: Modern Warfare 3 Grudge Match.
"The chairman showed last season that we are not a selling club. We can challenge next year for the title, definitely. We will be up there.
"We can achieve anything with the squad we have got. When I look around the changing room there's Gareth, Aaron Lennon, Rafa van der Vaart, Emmanuel Adebayor. There are world-class players there, experienced heads and they have helped me a lot this season.
"It's only upwards for Tottenham."
The defender had mixed feelings ahead of the Munich showpiece. While wanting Spurs to take the final Champions league spot, Walker was also keen to see an English team succeed in Europe.
"Obviously Saturday is football. That's what happens in the game," the 21-year-old said.
"I had mixed emotions as I know Ryan Bertrand, he was making his debut and Chelsea are an English team, but I want to test myself at the highest level so I favoured Bayern a little.
"It didn't work out as we would have liked but we just have to pick ourselves up now, dust ourselves down and challenge next year."
Walker also described his dismay at being ruled out of Euro 2012 with a broken toe and while he admits it was difficult to stomach, he wants to focus on the positives of a season that saw him pick up the PFA Young Player of the Year award and win his first senior international cap.
"It was difficult to take," the defender said.
"It could have been my fault. I had injections for the last three weeks of the season but I just wanted to play for Tottenham.
"I just wanted them to get in to the Champions League.
"But footballers have these setbacks in their careers and otherwise it's been like a dream for me this season, a perfect year."