Martin O’Neill has been desperate to boost his options at the heart of his back four during the transfer window after seeing Carlos Cuellar and John O’Shea join long-term absentee Wes Brown on the treatment table.
O’Neill needs to strengthen his defensive options both in the short and long-term.
The Sunderland boss admits the problem has become a concern after being left with just two fully-fit central defenders, Titus Bramble and Matt Kilgallon.
But neither Bramble nor Kilgallon are likely to be offered a new contract to remain at the Stadium of Light when their current deals expire in the summer, while doubts remain over Brown’s long-term fitness after a year on the sidelines.