I don't think Real Madrid will have a hard time winning the match against Ossasuna even though Benzema is not available. Real Madrid with better quality players will be very easy to dominate the match and score goals but I hope Ossasuna is not too weak in the match. Vinicius, Valveldre, Rodrygo are in good form and I think they are reliable too.
So far Ossasuna have won 4 of 6 matches, and until the 6th week their defense is still pretty good with only conceding 5 goals. I can hope Ossasuna does well even though Real Madrid are the favourites. 3-0 is possible, but Ossasuna might also score this away match.
Seems last announcement from Real Madrid social media about Karim Benzema have back training with the team and still not update yet he can play against with Osasuna or not depending he got injury and still need recovery time. Not problem for Real Madrid without Karim Benzema because last winning before break out from FIFA matchday against with Atletico Madrid success won with Rodrygo replacement for Karim Benzema position.
Depending on stable position standing seems Osasuna is not easy for Real Madrid with impressive performance in this season won 4 of 6 match, could be warning for Real Madrid never underestimate with Osasuna because have chance to stop Real Madrid winning record in 6 games before.