Unless I'm reading it incorrectly, the system randomly changes just one of your players that misses the cut ( not the Captain or V/C) for a player who did make the cut.
No choice as to who goes and who comes in. And it won't be someone currently in the top 10....
A bit convoluted if you ask me, some Fantasy games are seemingly getting more complex for the sake of it...preferred the previous system of 10 picks, 1 Captain and no changes..
I believe the random pick is if you forget to change your team and one of your players isn't playing they then remove the player and pick someone else who is playing ?
There's an Auto replacement thing that checks your team before cutoff and swaps players who aren't in the field for ones that are, randomly.
The system also ,once activated, will swap one missed cut , withdrawn, dq'd player for one who has made the cut after round 2 .