Centre Mike Tindall's return to the Recreation Ground - he quit Bath for Gloucester earlier this year - provides added spice, while his new club have failed on all 14 previous occasions to beat their neighbours away from home in league combat.
Both teams are also on form, with Bath unbeaten in their last three league and cup games and Gloucester having recorded five wins and a draw during both competitions this term.
"It really is a good game for us, coming at the right time as we have won our last three matches, while they are undefeated this season," said Bath rugby director Connolly.
"Add to that the England angle and the Tindall factor, then this game is set to be a real test.
"We know the threats that Gloucester pose, but we also know what we are capable of. It will be a hugely confrontational physical battle, but we are assured in what our pack is capable of."
Bath's loss was Gloucester's gain when World Cup winner Tindall migrated north up the M5, and he has already made an impact through a series of assured midfield displays.
"You always want to play well when you go back to your old club," said the Yorkshireman, an integral part of England's autumn plans.
"You always want to be fit, play well and win. Hopefully, all those things will happen on Saturday.
"We know it's a massive game. In past seasons, Gloucester have been the form team going down there, but then let themselves down a little.
"If we can get everything right that we've done in the last five games and build on that, as we've still got to improve in a lot of areas, then it is going to be a close game.
"Close games always seem to be the case in local derbies, and it might be a penalty that decides the match."
London Irish rugby director Brian Smith has rallied his players for the clash at Northampton by claiming: "We are treating the game like a Test match."
And if a recent Premiership trend between the clubs is continued, then Irish will win, given the away side has triumphed on seven successive occasions.
"We desperately want to come away with the points," said Smith, who hands first starts of the campaign to full-back Michael Horak and Dominic Feau'nati, with South African import Faan Rautenbach on bench duty.
"The players have worked hard in training this week, and they remain committed to playing positive rugby."
England hooker Steve Thompson, having started Saints' last three league and cup games at blindside flanker, reverts to his normal position, albeit as bench cover for Dan Richmond.
"Steve was playing really well at six, but he wants to go back to hooking," said Northampton rugby director Budge Pountney.
"However, Dan Richmond has played extremely well for the past four games and deserves his place.
"If Steve comes on and makes a great fist of it, then that will be great for the team, but if Dan is going well, then there is no point in making a change."
Sunday's Premiership action offers a mid-table encounter between Bristol and Saracens at the Memorial Stadium, with Saracens needing to become upwardly mobile following a poor start which already includes two defeats on the road, against Wasps and Worcester.