Last January Tottenham were within touching distance of the Premier League summit, but their north London derby loss at the Emirates Stadium triggered an alarming meltdown which ultimately cost the club a place in the Champions League, and Harry Redknapp his job.
A poor run of just one win in nine matches saw Spurs slip from second to fourth, with Chelsea's victory in the Champions League final in Munich providing the hammer blow for their neighbours' dreams of playing among Europe's elite this term.
Andre Villas-Boas, the man brought in to replace Redknapp last summer, has guided Tottenham to third and while his team are huge outsiders to top the table come May, finishing third or second is a distinct possibility.
But Walker knows the team cannot afford a repeat of last year's collapse if they are to succeed, making fixtures like Saturday's trip to Redknapp's new club, QPR, must-win affairs.
"Last time we faded off in the second half of the season," Walker told Spurs TV Online.
"Things like that happen, it's just football, but this year we have said that we are going to kick on around Christmas and the new year so we can get that third spot
"It's very close up there this season. The two Manchester clubs are a bit away, but then there's us, Chelsea, Arsenal, Everton and West Brom.
"That makes it exciting. It keeps you on your toes. And going to teams that are struggling like QPR, you know you need to get those three points to keep in contention to make sure you are there at the end of the season."
Before casting doubt on Redknapp's assertion that you had to be a "dope" not to be successful at Chelsea, Villas-Boas warned that QPR may be trickier opponents than they appear on paper.
Five points from safety, QPR look in serious danger of being relegated, but Villas-Boas warned that Redknapp's knowledge of the Spurs squad could give the 65-year-old an advantage over the favourites.
But Walker, who spent six months at QPR on loan two years ago, insists Spurs will not have any problems overcoming the west London club if they play to their potential.
The England right-back said: "You never know what might happen in football, it's a weird sport, but if we play as we have been doing we'll have no trouble."
Villas-Boas got his reward for dragging Spurs up the table today when he was named Premier League manager of the month for December.
QPR have lacked the consistency Villas-Boas has brought to Spurs and the Portuguese thinks that could be a key factor in whether the Rs survive.
"When negative results happen it's very difficult for you to come out of them," the former Chelsea manager said.
"You need a consistency in terms of results and only that will make you jump out of a crisis situation.
"I think Mark Hughes was looking for that stability, which never happened. Harry was looking for that stability too, which took some time, and it arrived maybe when people least expected it with the win against Chelsea and the draw against West Brom.
"Once they get that consistency they will get more confidence.
"As soon as they pick up that momentum I think anything can happen."
Villas-Boas has the rare luxury of an almost full-strength squad to choose from for Saturday's lunchtime game.
William Gallas is at a clinic in France having treatment for his calf injury while long-term absentee Younes Kaboul remains sidelined with a knee injury.