A member of the Broncos coaching staff has stepped away from work to fight an aggressive form of cancer. Denver passing game specialist Zack Grossi, who is in his third year on the Broncos’ staff, started chemotherapy this week after he was discovered to have a yolk sac tumor in his chest. Grossi, 35, said in a message shared with the team’s website that he first started feeling off a few months ago. From his message: “For the last three months, I felt a little bit off, and recently, I began to have trouble breathing.