I once dated a linebacker. His job was to either give extra run protection or pass protection on the defensive plays. It was pretty neat.
did he play professional
No. He played on just a regular American football team. They also have football teams in Canada. Being a linebacker is often regarded as the most important position in defense because of its versatility.
oh I dont know much about football, he must have been in good shape to play that position
Yes he was, and smart too! He learned about the early history of American football and how it could trace its inception from rugby football.