The 40 centre backs available to Birmingham City for free this summer

Birmingham City are sure to have a busy transfer window this summer with players out of contract, others out of favour and attempts to reallocate resources in Lee Bowyer’s squad. Every position is likely to come under scrutiny but nowhere more so than in defence where injuries have crippled Blues this term.

Left-back/left-sided centre back Kristian Pedersen will leave at the end of the campaign and the club are expected to try to move on former captain Harlee Dean. Marc Roberts and George Friend remain, as does rising star Nico Gordon - but Blues are likely to want more depth.

As a rule Blues want to pay their fees for younger players while accepting there is value in older free agent - and there are going to be plenty of those this summer. Here’s a list of options both in the Premier League and Championship. Some might be fanciful, others have already started talks with their current clubs - but many are sure to move on.

James Tarkowski, 29, Burnley

Zanka, 31, Brentford, one-year option

Julian Jeanvier, 29, Brentford, one-year option

James Tomkins, 32, Crystal Palace

Jaroslaw Jach, 28, Crystal Palace

Fabian Schar. 30 Newcastle

Jack Stephens, 28, Southampton

Angelo Ogbonna, 33, West Ham

Romain Saiss 31, Wolves – contract offered

Sol Bamba, 37, Middlesbrough

Yoann Barbet, 28, QPR

Chris Basham, 33, Sheffield United, one-year option

Ciaron Brown, 24, Cardiff City

Gary Cahill, 36, Bournemouth

Eiran Cashin, 20, Derby

Curtis Davies, 36, Derby

Tobias Figueiredo, 28, Nottingham Forest

Aden Flint, 32, Cardiff City

Michael Hector, 29, Fulham, one-year option

Tom Holmes, 21, Reading

Paul Huntington, 34, Preston

Richard Keogh, 35, Blackpool, one-year option

Timm Klose, 33, Bristol City

Darragh Lenihan, 27, Blackburn

Tyler