The victim was approached by two other men and pushed to the floor where he was hit across the head.
It happened at the Old Cross pub, on Causeway Green Road in Oldbury, on October 22 at around 11.50pm.
Anyone with information should contact the force via their website and quote 20/923487/22.
Alternatively, information can also be given to Crimestoppers anonymously on 0800 555 111.
