Boss Chris Boyd expects Saints to show 'extra bite' as they bid to beat Leicester Tigers at Franklin's Gardens on Saturday.
Boyd's men know a bonus-point win against their local rivals will secure a semi-final spot in the Premiership Rugby Cup.
Leicester only have the east midlands bragging rights to play for as they have lost all three of their games in the competition and can't qualify for the final four.
But Saints have plenty of incentive, and they will be desperate to secure a big win against their familiar foes.
"We love playing at the Gardens anyway, it doesn't matter who we play, but Leicester gives us that extra bite," said Boyd, who will be sampling his first Franklin's Gardens derby.
"As I'm starting to find out, it's a very traditional derby and we'll certainly be treating it with that respect.
"Obviously Leicester at home is always a pinnacle game so we're excited about that.
"It might be in a slightly different competition but the boys are still considering it to be Leicester at home and we'll prepare accordingly."
Saints, who lost to Leicester at Twickenham in October, have plenty of selection options this week with the likes of James Haskell and Ken Pisi now available.
And with a free weekend next weekend, Boyd is eager to get the balance right.
"It (selection) is a mixed bag," said Boyd.
"Last week (for the 111-3 Challenge Cup win against Timisoara Saracens), we made 12 changes to the starting line-up from the Clermont game and we've now got this game, a bye and then the unknown of whether we'll qualify for the PRC semi-final the week after.
"We're trying to keep the guys going who need that, rest the players who need to rest and bring on the guys who need to be brought on.
"It's horses for courses.
"There will be a few guys who didn't play Timisoara last week who have been regulars in the first-team selection and who need to get going again.
"But a significant amount of players have got a statement to make.
"We've got really healthy competition across the whole squad and though you never like to lose your best players, we generally feel we've got good depth and can cover most positions."