The former German international had signed for Bolton but has since reneged on that agreement.
"Bolton Wanderers wishes to clarify that although Didi Hamann signed a contract with the club, he has since had a change of heart and will sign for another football club within the next 24 hours," a Bolton statement read.
Stuart Pearce has been targeting Hamann all summer and could now jump in and make him his 4th summer signing after Paul Dickov, Ousmane Dabo and young goalkeeper Joe Hart, from Shrewsbury.