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

Lindberg becomes one of Sajer's closest friends and a constant companion. When a Gross Deutchland recruiter asks for volunteers from Lindberg's transportation unit, Lindberg volunteers to join the infantry with the others. He is trained alongside Sajer, goes on leave at the same time, and is later deployed in the same unit under Hauptmann Wesreidau. He remains with Sajer and Hals throughout the entire war.