 He was raised to the rank of Privy Chamberlain of His Holiness on 9 January 1923, and later Domestic Prelate of His Holiness on 5 April 1933.He then served as auditor (1924–1933) and "chargé d'affaires" (February to September 1933) of the Apostolic Delegation to the United States.On 15 September 1933, Marella was appointed Titular Archbishop of Doclea by Pope Pius XI.