If you have big shoes to fill it means taking over a role from someone who was very capable or respected, and people have high expectations of you.
The phrase uses the image of stepping into another person's shoes. When the shoes are large, the new wearer is measured against the person who came before.
The phrase uses the image of stepping into another person's shoes. When the shoes are large, the new wearer is measured against the person who came before.
The new coach knew he had big shoes to fill after the previous coach retired.