Some suggestions from me:
GK : Jason Steele (Blackburn), Kieran Westwood (Sheffield Wednesday), David Marshall (Cardiff).
IV : Michael Keane (Burnley), Harry Maguire (Hull), Liam Moore (Leicester), Marc Wilson (Stoke), Daniel Agger?(Bröndby), Christopher Samba (free Agent in the Summer) or something different like Marco Russ (Frankfurt).
RV,LV : Luke Garbutt,Todd Kane (for another loan move from Everton/Chelsea), Phil Bardsley (Stoke) or something different like Santiago Garcia (Werder Bremen).
DM/ZM : Gareth Barry of course, Vadis Odjidja-Ofoe (Norwich), Liam Bridcutt (Sunderland), Tom Huddlestone (Hull,running out of contract), Peter Whittingham (Cardiff), John Fleck (Coventry), George Thorne (Derby) or even Alex Mowatt (Leeds). I would love Will Hughes but I doubt this is possible.
RM/LM : Anthony Pilkington (Cardiff), Serge Gnabry (Loan from Arsenal), Matt Phillips (has not the best of seasons but he's still quality IMO), Ryan Fraser (Bournemouth(on loan to Ipswich), Stuart Dallas (Leeds), Ahmed Elmohamady (Hull) or something different like Yeni N'Gbakoto (Metz).
OM : I agree with Zach Clough, Alan Judge (Brentford), why not bring back Stephen Ireland (Stoke), Jonathan de Guzman (Carpi loan from Napoli) or why not loan a hungry youngstar like Kasey Palmer (Chelsea).
ST : Dwight Gayle or Fraizer Campbell (Crystal Palace), Peter Crouch (Stoke), Simon Terodde (Bochum), Will Keane (Man Utd), Britt Assombalonga (Forrest), Steven Fletcher (Marseille loan from Sunderland) or something different Eduardo (Shaktar,will have bids from the Chinese SL I believe...).
I know this is a lot, and I doubt that you will agree with all of them.
Pls give me a feedback for my first post. In witch casses do you agree with me. I know my suggestions were often older players.
For sure we should get some younger players as well. I mostly picked the more experienced players who I think could help us back up.