Jim Nelson

Jim Nelson is regarded as the second best neurosurgeon at Seattle Grace Hospital

Career
Dr. Nelson was the interim chief of neurosurgery before Derek was hired.

According to Callie, he is a good surgeon, publishes a lot of research, but because he isn't Shepherd and Richard's golden boy, he falls to the sidelines frequently, so much so that Richard does not actually consider him for any of Derek's surgeries when Derek "leaves". Mark has also failed to notice him in the time he's been working at Seattle Grace, despite Jim working there longer than Mark has.