The phrase "poisoned chalice" means something that appears beneficial or desirable, but is actually harmful or problematic when obtained or taken on. Full definition
A recent home affairs committee report showed that the granting of asylum often turned out to be poisoned chalice for those fleeing persecution, with the approval decision activating a period of financial uncertainty which lasted up to four months. (politics.co.uk)
If they do decide to give him the job and they still go through the same motions then it is confirmation that Sunderland are the biggest poison chalice in football management. (eplindex.com)
A well paid poison chalice, probably like most elite manager jobs in this game. (untold-arsenal.com)