With Flick complaining that his men didn't get much rest since some of them just returned from international duty not too long ago and now have their game with Osasuna, don't you think the performance of Barcelona will drop a bit? In other way too, if you look, 80% of the squad members are Spanish and they finished their game earlier on so what's with him making a fuss. The way Barcelona are now, I feel that even though they have just one day to get ready for a game they can still give a beautiful performance.
Madrid and Barcelona are on the same points so winning this game is a must so that they can have an edge over their competition and even though Osasuna can cause trouble for them, I still don't think they will be so troublesome enough as to cost them the three points.
With several players who may still be tired, Barcelona may not be as strong as usual. But still Barcelona will be the favorite to win the match. And Barcelona will also have the ambition to beat Osasuna this time. Because in the previous meeting, if I remember correctly, Osasuna managed to beat Barcelona, right? and yes, Barcelona will be motivated to avenge their defeat in today's match.
Because if Barcelona fails to get full points in this match then it means Barcelona cannot restore their reputation which was previously defeated by Osasuna in their last meeting. Osasuna is by no means a weak team. But their strengths and Barcelona are actually a little different. So even with the current conditions, Barcelona should still be able to overcome Osasuna's game. Although several Barcelona players may be absent. But the players available I think are enough if only to beat Osasuna.