(Note: I enjoyed reading this article; opens up the whole debate about who we should sign in the summer, so any suggestions?)
It's hard to refine perfection, but, because I'm not in my senses now (after the classico L ), I will attempt it. I have seen Barcelona struggle on the left wing for far too long and thus my suggestions are mostly to improve that. This is how I would like to view the team at the start of next season.
I will start with the most important position and man, and NO, I'm not talking about Lionel Messi. I'm talking about our manager, the one and ONLY Super PEP. He obviously has to continue; to redefine football, to surprise us with his tactics, and to better what he has so fondly and perfectly built over four seasons.
Outs: Adriano, Keita, Afellay, Fontas, Jonathan Dos Santos
Ins: Eden Hazard, Jordi Alba, Romeu (ideally another world class CB, but probably not possible in the budget after these ins and outs. Abidal could excel at CB once-in-a-while if Alba can consistently play week-in and week-out without getting tired at LB)
The left flank has persistently been a problem, and so most of the attacks are always through the right flank through Alves, and although he combines brilliantly with Messi, the team becomes too predictable and thus it's not effective. Also, playing without a traditional big CF, Alves crossing tends to limited and not particularly dangerous, so he's always looking to cut in and pass, again leading to predictable attacks. Thus, the left flank needs to be strengthened considerably, and Alba and Hazard would be perfect to shore it up. Alba has proved how good he is both defensively and while attacking, and he could help maraud the left flank much like Alves on the right. Though Hazards work rate has been questioned in the past, he is brilliant on the left flank and is extremely tricky, and can dribble, beat defenders and create space.
Lastly, from the little I have seen of Romeu in his time at Chelsea, he seems well suited to Barcelona's play (not sure why they sold him in the first place). He is tall (like Busquets) and strong, tackles well, and his passing is particularly good (maybe not compared to Barcelona players, but he is much better than average and looks brilliant in the Chelsea team) - calm, and nice short passes. He seems to be able to read the game pretty well also. He looks a better option than Keita at least as CDM.
I really don't see Jonathan Dos Santos making the step up to the first team ever, and he has looked nothing better than average at best whenever he has played for the Blaugranas. Same, or probable worse for Fontas. Everytime he has taken to the pitch, he nearly gives me a heart attack (will probably become the Johnny Evans of Barcelona if he continues), and I don't think he is the red and blue's class.
As for, Adriano, Keita, and Afellay, they seem to be surplus to requirements mostly. Adriano has been average and cannot be trusted for big games. Plus with Alba coming in, it could be time to cash-in on him. Same for Keita; he is aging and although he has contributed extremely well during his time at Barcelona, it's probably best to move him on and invest in Romeu or another strong midfielder. Afellay is probably the most unfortunate; with Hazard coming in, we would have 6 attackers (not counting Tello), and being non-Catalan and not a graduate of La Masia, I would rather sell him than the others.
SQUAD (the ones in bold should be fringe players from B team brought in when required)
Manager: Pep Guardiola
Forwards: Messi, Villa, Sanchez, Hazard, Pedro, Cuenca, Tello, Deulofeu
Midfielders: Xavi, Iniesta, Busquets, Fabregas, Thiago, Romeu, Sergi Roberto
Defenders: Alba, Abidal, Puyol, Mascherano, Pique, Alves, Bartra, Montoya, Muniesa, Sergi Gomez
Goalkeepers: Valdes, Pinto, Mino, Oier
Given this squad, we could manouvre a lot.
Puyol can double up as RB for Alves, while Abidal can cover at CB with Alba at LB. Villa could play as CF or RW or LW, Sanchez at RW or CF, and Pedro on either flank.
Puyol, Abidal, and Xavi could get sufficient rotation and rest as well without having to play insane minutes.
Team: 4-3-3; With Messi as CF
If Messi needs to rest, we can still field Villa as CF without compromising the left wing (Hazard) or right wing (Sanchez). It will still be the scariest front 3 -- Hazard, Villa, Sanchez.
Team: 3-4-3; With Messi as attacking mid
Subs: Villa for Hazard/Sanchez, Fabregas for Xavi, Mascherano for Puyol
It's a toss-up between Villa and Hazard depending on the game:
If Alba can go up the flank to attack without worrying too much about defence (for easier games maybe), I would start with Villa instead of Hazard, so that he could come in and shoot/make runs.
If we need someone to stay wide and open up the pitch, I would start with Hazard on the left as he can dribble better, take-on and beat defenders and create space.