The black, green and gold are ready to rotate after suffering three defeats from as many Champions Cup matches so far.
Saints have a key Gallagher Premiership encounter at Worcester Warriors next Saturday and are set to be without their four England players for that game.
That means there is a big chance for others to step up and show they deserve a run in the team beyond this weekend.
And the fact that this clash is as tough as it gets, as Racing 92 are among the favourites to win the Champions Cup, is perfect for Saints to see what their squad members can offer on the big stage.
"Selection wise, this is the ninth game of a 10-game block where every game has been Prem or European so we have to manage load - you can't just run the same team into the ground every weekend," Dowson said.
"We've been working out who needs rugby and who needs a rest so there will be elements of managing load for players.
"There's also the element that with the England contingent going away, Biggs (Dan Biggar) going away with Wales, with Scotland calling up Hutch (Rory Hutchinson), we have to make sure lots of players in the group have got game time and are ready to go for that Six Nations block.
"It's a double-edged sort of resting and recuperating players who have played a lot of rugby and also making sure guys have had enough rugby ahead of the next month or so.
"Whatever happens this weekend, it's an opportunity for that player.
"It might be an opportunity to change a coach's mind, it might be an opportunity to get some game time, it might be an opportunity to show what he's capable of at this level, it might be an opportunity to show how he's improved over a period of time.
"There are loads of opportunities as individuals but as a group we've got a great chance to go there, get stuck in and play in a really quality, unusual environment against a really good side.
"We'll find out where we're at and see if we're getting better.
"You find out about people when they're under that sort of pressure.
"It will be really interesting to find out what they're like when they're in the lion's den."
Saints will take on a Racing 92 side who have won all three of their pool games so far, including a 45-14 victory in Northampton last month.
"They've got an unbelievable lineout defence, they've got a big scrum and maul, they've got some big boys up front in the front three," Dowson said.
"They've got a good ball-carrying eight, they've got Wenceslas Lauret, who scored a hat-trick against us, so they've got some good athletes.
"In the backline, every one of them is an international and in Finn Russell they've got one of the best 10s in the world.
"It's a real good challenge for the defence and a really good test of how much we've improved and how we can exert pressure on their attack."