i found it a massive struggle on my game, obviously you need a left back as a starter, i found greg cunningham on a seasons loan from man city sorted that problem, as for the rest, depends on what formation you're planning on playing for one thing i guess??? i found i could get marcin wasilewski on loan from anderlecht at a good value, he ended up in my team of the year with an average rating of 7.4 at cb. you can sell paul smith, clubs are interested in him, and then pick up a keeper on loan (like Amos at Man Utd) that gives you extra funds to play with if needs be, if you let me know your formation then i can suggest other players going forwards