Yang Guangyuan
By that point, the Later Jin imperial government was in a tense standoff with Yang Guangyuan, who was then the military governor of Pinglu Circuit (平盧, headquartered in modern Weifang, Shandong), with Yang displeased that his powers were being curbed by Jing, and therefore was secretly negotiating with Emperor Taizong, hoping for Liao support for him to displace Later Jin. In late 943, Yang, in preparation for his rebellion, secretly ordered his son Yang Chengzuo (), who was then the prefect of Dan Prefecture (單州, in modern Heze, Shandong), to flee back to Pinglu's capital Qing Prefecture (). In spring 944, Du tried to defuse the situation by sending his staff member Cao Guangyi () as an emissary to Yang, trying to persuade Yang not to rebel. Yang initially promised that he was not intending to rebel, such that Shi believed his promise and tried to negotiate with him further. However, Emperor Taizong, around the same time, already launched Liao troops to aid Yang, and so Yang rebelled anyway. During the subsequent campaign, during which Shi ordered a number of generals to the north to resist the Liao invasion while sending Li Shouzhen to attack Yang, Du was titularly the second in command of this anti-Liao army, under Liu Zhiyuan. The Liao army was soon repelled, and Li Shouzhen's siege on Qing caused Yang Guangyuan's son Yang Chengxun () to put Yang Guangyuan under house arrest and then surrender.