Been saying it for a while now, even when things were going well, this team needs some serious help and some serious overhaul. This team has no claws, and without Messi, it is positively toothless. Not playing with a CF will continue to cost the team dearly time and time again. With Messi playing, he covers this deficiency because he is such a once in a lifetime talent, but even he would benefit from having a target man up front. But even with a CF, this team has a mountain of holes.
The team has been so badly mismanaged, for so long, now all the issues are piling up together. They have lived and fed on pass glories for far too long, and have done very little to future proof the squad.
The team has gotten slower and slower, has progressively lost on physicality year after year, and has become more and more toothless with each passing season. The issues are all over the place, and frankly one season of heavy acquisition will not be enough to patch up the team again.
You basically need an entire team.
Need 2 Keepers - One starter caliber, one good back-up for depth and competition.
Defense needs an entire overhaul. Need to get younger and more complete lateral players. It is sad that even with his very apparent decline, Dani Alves remains your best all around lateral player. Alba is a zero on defense. Need to get better CBs, even if Bartra has bought himself a spot, you need to get better talent than Pique, and need to seriously consider demoting Puyol to last resort option, if not retire him. Mascherano should never have played this much as CB, that is a travesty.
The midfield is slow as slow gets. Xavi needs a replacement ASAFP. Need to find a two way midfielder than can give Busi some frigging help, and has pace and control on offense. Iniesta has been very frustrating. He is holding onto the ball far too much both on offense and defense and is costing the team dearly. Cesc is inconsistent, but as an attacking midfielder, he has shown a lot of good, he should be starter at this position. IMO.
Front line needs a CF, now. This team is seriously anemic in scoring. This needs to be fixed now and even with Alexis good form he is not a reliable scoring option when you absolutely need it, he just isn't. Neymar is not a scorer yet. This team is fighting battles with both hands tied behind its back. They need perfect team play to score right now.
The team sometimes doesn't trust La Masia enough, and sometimes they trust it too much. It is ok to give youngsters playing time. Mascherano should NOT be playing ahead of Bartra, and at this point, Sergi Roberto brings more to the team than Xavi, on energy and work rate alone, sadly.
At the same time, La Masia does not have all the answers. Montoya is not a starting caliber player. He is average. He cannot be your future. Tello is too one dimentional, you need more complete players than him.
Barcelona is a world class team. I know Catalans have fallen in love with the "la cantera vs la cartera" idea, and have pumped their chests in pride at this. However, farm systems in football are complementary to transfers. Specially if you want to be at the top consistently. You can get magical generations, like Barca's, but you cannot rely on this forever. You need to go out there, scout and spend money to bring foreign talent, and then complement it with la Cantera.
The team also needs to learn how to let go of stars that have decline due to age and play. Nothing wrong with these players taking on a secondary role to replacements. It is for the betterment of the team.