A West Ham United spokesman said: "After what has been a traumatic period of time for Calum, we feel that it would be in his best interests to allow him an opportunity to put what has been a difficult few months behind him and restart his career afresh."
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The defender said: "I would like to thank everyone at West Ham for their incredible support over the last six months, especially the manager and the excellent medical staff who have helped me through my recovery.
"I would like to also thank the fans for all their messages of support.
"I understand that there is no longer a place for me in the team and wish the team every success for the future.
"I am fully focused on returning to fitness and aim to be back playing football for a new club by the start of next season."
Davenport was left with a 15 inch scar on his leg after being attacked by his sister's boyfriend and required surgery.
In January, Davenport pleaded not guilty to assaulting his pregnant sister, Cara, in the same incident.
He is due to stand trial at Luton Crown Court on Aug 2 and is currently out on bail.
West Ham are three points off the relegation zone and have been looking to cut costs since the arrival of new owners David Sullivan and David Gold in January.