That's a strange team: if you want to play using just the players that you already have you can actually win, with the proper tactics, everything.
In my case I'd truly love to work with younger squads, so that's what I actually didi in my last save:
- Sold: Nani, Welbeck, Javier Chicharito, Ashley Young, Buttner and Anderson.
- Bought: Gotze, Fellaini, Lars Bender, Goretzka, Vadillo, Maher, Wellington Nem, Ademilson and De Ceglie.
Team:
De Gea
Rafael
Ferdinand/Jones
Vidic
Evra
Lars Bender
Fellaini
Carrick
Gotze
Rooney
Van Persie
This team is young, has a lot of "bite" and is technically gifted. You will have problems to blend this team, which will take a disturbing... 6 months, 3 or 4 at least. BUT... after that, wow, just... wow.
Goretzka develops fast if you put him to play sometimes, Maher too and Ademilson I pretty much think he's a "bug", because he can actually start playing right away, so is Nem, but Ademilson's impact is felt from the beginning.
In fact, people say that Javier is goal machine and Welbeck turns out pretty good, BUT... Ademilson is so good that I felt I didn't need those two.