Abu Umayr bin Anas (may Allah have mercy on him) said: My paternal uncles from the Ansar, who were Companions of the Prophet (peace and blessings be upon him), narrated to me that the Prophet (peace and blessings be upon him) was concerned, and he narrated the hadith. In it, it says that Sayyiduna Abdullah bin Zayd (may Allah be pleased with him) was ill in those days, and the Ansar claim that had he not been ill, the Messenger of Allah (peace and blessings be upon him) would have made him the mu'adhdhin.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 1874