I would get rid of two of your goalkeepers, get some money out of them. Plus I'm sure they'll become unhappy at being left out anyway. Always look to strengthen certain parts of your squad, so I'd sell Bouma or Shorey, don't sell both. This is so you can buy a much better left back, while have another for cover. Thus strengthening the left back position. If money is available, I would also sell Gardner and bring in a new Creative Defensive Midfielder, as Reo-Coker is a hard worker, I would rather have a Hard Working DM & Creative DM rather than two of the same. So I'd reccomend Hamsik, Alonso, etc.
So in summary.
Sell: Bouma / Shorey, Gardner, Friedel / Guzan / Taylor (Sell Two)
Buy: Creative DM, Quality Left Back.
If you haven't got enough money, choose one (Left back or Defensive Midfielder). But if you'd like to get both, I'd suggest selling those who rarely get any appearances. But this could prove costly in the second half of the season, as you wouldn't have a big squad so players will be tired. So if you do, get in some loan players to cover.