Where are we hiding these useful midfielders you are talking about
Exactly! Gomes is obviously a lost cause, Rafinha i like, and he can be useful, when fit. But he can't stay fit for a whole season, and isn't THAT great. And the same goes for Denis, without the fitness issues. He may show flashes of usefulness, but he clearly won't ever be good enough to be anything than a squad player in a first class club like Barca. A second or third class club like Napoli or Villarreal he can be great for, but not Barca. That said, if he's content on playing only those 10-20 games per season and on low wages, i guess he could stay, but i don't see much point in sticking with him, not to mention he could really hinder Alena's development.
All these players have had at least 2 years in our club and have shown time and time again that they can't cut it, let it be because of fitness, consistency, or quality issues. It's time to cut our losses and move on, tired of having all these mediocre quantity of players contracted to our club, pulling great wages (we all know we have the highest wages in world football), but not contributing enough to be earning them.
Especially when there's great young players like De Jong and Arthur and La Masia graduates like Alena, who seem to fit our style perfectly (Arthur) and would love to play for us (De Jong), not to mention, are of great quality for their age and will only get better, you can just see it when watching them (especially De Jong and Alena, i'm not that sure about Arthur yet).