As Emperor Ming neared death in 325, he entrusted his four-year-old son Crown Prince Yan, by Yu Liang's sister Empress Yu, to a number of high-level officials, including Yu, Sima Yang (司馬羕) the Prince of Xiyang, Wang Dao, Bian Kun (卞壼), Chi Jian (郗鑒), Lu Ye (陸瞱), and Wen Jiao.
In 327, apprehensive of Su's ambitions, Yu became intent on stripping him of his military command, and he promoted Su to the post of minister of agriculture in order to do so.