The San Francisco 49ers gave Brock Purdy a huge extension earlier this month. Now, he has to prove that he's worth the payday.

Evaluations of quarterback Brock Purdy seem to swirl around one particular factor—supporting cast. The argument goes like this: He is surrounded by playmakers, and his head coach is a genius who can scheme success out of anyone,

Kyle Shanahan has to prove to 49ers ownership that he's the right coach for Brock Purdy while he's being paid a ton