Who is Lindberg from The Forgotten Soldier and what is their importance?

Lindberg was one of Sajer's closest friends and his constant companion. He trained with Sajer, went on leave at the same time as Sajer, and was finally deployed in the same unit as Sajer under the command of Hauptmann Wesreidau. The two fight together throughout the entire war. Sajer notes that Lindberg wasn't the bravest of men, and often suffered form bouts of heightened nervousness before battle. Unsurprisingly, Lindberg suffers no injuries during the war and survives to surrender to British forces on the western front.