At this point in the year, it's Dangerfield or Stevens IMO because both neither has an equivalent backup. Dangerfield does a good know of knowing when to step up and when to deflect to others. She's the best playmaker on the perimeter and makes good decisions. She's become one of the best PGs in the country. If she disappears, there isn't someone to fulfill that role. Stevens provides size and low block ability that no one else on UCONN possesses. UCONN likely has 2 losses if not for Stevens stepping up against Notre Dame and Texas. My guess is that in any other close games this season, UCONN will look to Stevens inside down the stretch.
I'm shocked I'm not saying Gabby Williams, but she hasn't been the same player this year. She is by far the most talented player on the team, but she's been up and down all year. I think her regression has been the biggest difference between last year and this year. When she's playing well I don't think there's a better player in the country. She can dominate a game defensively and creates easy opportunities for herself and others. She dominated Brianna Turner head to head and dominated South Carolina's frontline of Wilson and Coates. She does everything exceptionally well besides shoot the ball. Last year she brought a different intensity/edge that permeated throughout the rest of her team and that seems to be missing this season. If she finds that and starts playing like she did, I don't think we'll see any other close games.
As far as the other players--Collier has been up and down and can disappear so it's not her. KLS should take home the AA hardware this year, as she's been UCONN's best player IMO, but we've seen her miss games and UCONN doesn't skip a beat. She's the best scoring threat on the team, but she doesn't bring anything to the table that another player can't replicate. Same with Nurse. If either one of them go down, Z enters the lineup and players rotate over and all of them get more shots. They not be quite as efficient or productive as KLS or Nurse, but if anything it'll be just a slight downgrade.
If you lose Stevens, you're stuck with just Collier and Williams defending posts (good luck against Brown/McCowan/Wilson), and if you lose Dangerfield, you have Nurse running the show who doesn't bring the same PG qualities to the table that Dangerfield does.