"In a sense it's 15 blokes against 15 blokes on the pitch and whoever's better on the day wins it," Waller said at this week's media session.
However, he doesn't underestimate the significance of that battle between those 30 blokes.
He knows what a win at Mattioli Woods Welford Road would mean for Saints this Saturday, especially as the Gallagher Premiership final at Twickenham is the prize for the victors.
But Waller, who has played 329 times for Saints, will be doing what he can to keep his cool on what is sure to be a heated day.
"I've been fortunate to play in 20-plus derbies now and each one has it's own story - this is just another one in that," Waller said.
"It's important for us as a squad and as a unit to play the game, not the occasion.
"You can get tied up in the occasion and lose the game as a result, so for us it's about doing what we're good at.
"The edge is going to be there, the hype and aggression is going to be there, and there's the extra pressure of it being at semi-final as well.
"It's really important for us to play our game and focus on the process."
So has Waller become calmer in the build-up to, and during, games against Tigers over the years?
"I don't think calmer is the right word - I think I know how to take those emotions and process them in a positive sense," said the 32-year-old.
"On derby day, there's always going to be a physicality and an extra 10 or 20 per cent from everyone - that's why people love watching it.
"I know what I need to do, my job in hand and you realise doing anything stupid is detrimental to the lads and I just want to do my best for them.
"Long gone are the days when scraps were allowed and punches were thrown on the sly.
"Nowadays, you can cost your team so there's no point doing it."
Saints are well aware that they must stay on the right side of referee Matthew Carley this weekend.
But just how can they do that while still fighting fire against a Tigers side who pride themselves on their immense physicality?
"There's plenty of ways and I'm not going to give too much away," Waller said.
"There's plenty of ways to exploit what they do.
"Don't get me wrong, they've been fantastic throughout the season and they are the first team to play the whole season on top of the table.
"There are holes in their game we can exploit with the way we play - and that's what we're going to be looking to do at the weekend to hopefully end up at Twickenham the week after."
The fact that Saints are even part of this occasion is something for them to be proud of, when you consider they had dropped down to the lower reaches of the league at one point this season.
They have put together an incredible run of results, taking 32 points from the past 35 on offer in the Premiership.
And it seems a March 5 defeat at Gloucester - their fourth in a row in the league - proved to be the turning point.
"As a playing and coaching group, we had a sit down and said we've got to take the bull by the horns," Waller said.
"We had to decide where we wanted to be. If we wanted to just finish sixth and qualify for Champions Cup rugby, that's that but not a single hand went up for that option.
"We all developed and came together to say we've just got to play our rugby and do our job.
"When we focus on us, it seems to pay dividends."