Concerning Barcelona and Osasuna, do you know when you have a target that is greater the other person's target you will so much pressed to make sure or ensure that your target is met. So Barcelona target is to maintain or if possible increase the point difference between them and Real Madrid so that they will be somehow relax and no matter how Osasuna play, I doubt if they can even see a draw just that football is something that is very hard to depict what the possible outcome will be and so I won't be surprised also if I see the reverse of what I have just said.
Most people will be more confident of Barcelona winning because it is about the opponent that Barcelona will face, Osasuna. Everyone can see that Osasuna is a team that has not developed well this season so it is clear that it will not be difficult for Barcelona to win at home when hosting Osasuna. Moreover, Barcelona are also quite aware that the match is to create a gap in points with Real Madrid so the home team will not ignore that opportunity this weekend. So those who hope for Barcelona to win I think it is very logical because considering their opponent is not too strong.
Barcelona are going to win against Osasuna because Osasuna are not in their best form, while Barcelona's current performance in the La Liga competition – I don’t think there is any team in La Liga that can easily bring Barcelona down at the moment.
Barcelona being at the top of the standings is another motivation for them to hunt for a win in this match so they can secure more points to make their position stronger, and Real Madrid are coming near to them, and they must chase more wins to secure their position well and more points to give Real Madrid enough gaps in what they currently need at the moment.