How does the author use foreshadowing in The Fighting Ground?

Early in the novel, the tavern keeper appears to hold back an unpleasantness in regards to the Corporal and his behavior, though he will not reveal it when pressed by Jonathan. This foreshadows trouble ahead in regards to Jonathan's dealings with the Corporal. The tavern keeper's suspicion buoys the initial impression the reader has already formed of the Corporal based upon physical description alone, when the Corporal is described as having filthy clothes and pock-marked skin.