I really do, I hope he returns to help his side get to the finals, because I see no other club but Napoli winning the Champions League this season.
Victor Oshime has been a plus for the squad, coach, fans and every person part of the club. Although he's absence wouldn't affect them much despite the big role he has with the squad. I hope the defenders are ready, Milan are big time European Competition giants they shouldn't sleep and mess around.
Talking about Napoli winning the Champions League this season looks a bit early, as they need to overcome many hurdles. They might look lucky because they will face Milan, and if they won they are supposed to face Inter Milan, and both teams are well known to them as they play in the same League, but the other branch of the competition will result in Real Madrid, Manchester City, or Bayern Munich in the final, and all these teams seems stronger and more experienced than Napoli who qualified for this stage for the first time in their history.
Regarding Osimhen, his appearance would add to the team for sure. Another point, in my opinion Spalletti didn't want to uncover his plans for the Champions League, maybe that was the reason for their loss against Milan in the Serie A