Celta has only 3 points more than Rayo.
Actually, Celta is better than Rayo ONLY because they won against us at Nou Camp.
So, this is not THAT easy match.
Further, for example, Rafinha was a starter in both losses at home.
It could be a pure coincidence, but...
But I would rather have the strongest lineup now, whenever possible.
Also, we have 6 days of rest.
Messi and Suarez have to play, since we are missing Neymar.
Rakitic and Iniesta have to play, since Masch will be a DMC.
Dropping one out of these 4 players would be insane.
In the defense, why resting anyone?
1. they will have 6 days of rest
2. plus, the defense will be slighty out of sync with Masch at Dmc already.