司馬懿
In 238, the Wei court summoned the Grand Commandant () Sima Yi for another campaign against Gongsun Yuan. Previously, Sima Yi had been tasked with defending Wei's western borders from Shu Han's Northern Expeditions led by the Shu chancellor Zhuge Liang, so when the latter died in 234, the government of Wei became able to afford sending Sima Yi to another frontier. In a court debate prior to the campaign, the Wei emperor Cao Rui decided that Sima Yi should lead 40,000 men for the invasion of Liaodong. Some counsellors thought the number was too many, but Cao Rui overruled them, saying: "In this expedition of 4,000 "li", mobile troops must be employed, and we must exert our utmost. We should not mind the expense at all." The emperor then asked Sima Yi for his assessment on Gongsun Yuan's possible reactions and how long the campaign should take, Sima Yi responded as thus: