All these facts are should be alarming, because despite the fact that many players have returned from national teams and have not had time to rest properly, bookmakers still consider Barcelona as a clear favorite with odds of 1.27 to win and it is very strange. Osasuna is in 14th place in La Liga and is not an outsider or a contender for relegation, so Osasuna is quite capable of playing a draw, given that in its lineup Ante Budimir, who has already scored 15 goals this season, and the Barcelona lineup will not be optimal, so I would not be as confident in the victory of Barcelona as bookmakers and to score a goal and try to draw with Barcelona Osasuna probably should.
That's because even Flick decides to rotate 80% of his first 11, they are still stronger than Osasuna. What bookies look out for mainly is team strength, team depth, previous meetings that's H2H and sometimes team names. For instance, we all know that Manchester City is deep in form from the Premier League but even if they meet a team like Nottingham Forest that's above them, there's every chance that Manchester City will still get a smaller odd compared to Nottingham Forest.