Siemian Throws Pick-6, Sanchez Takes Over, 49ers Expose Broncos' Defense

DENVER (CBS4) - Right when it looked like Denver Broncos quarterback Trevor Siemian was the front-runner for the starting quarterback position, he threw a Pick-6 against the 49ers.

It's an ongoing evaluation at the quarterback position and it will be a tough decision for head coach Gary Kubiak.

Devonte Booker was carrying the load at running back in the second quarter. He's battling to be C.J. Anderson's backup.

Broncos linebacker Cory Nelson suffered a wrist injury and his return is questionable.

The Broncos defense finally gave up points. The San Francisco 49ers were able to drive the ball midway through the second quarter and score a touchdown. After the score the 49ers lead the Broncos 14-7.

Mark Sanchez took over for Siemian at quarterback following the 49ers score. He hit Cody Latimer for a big gain on his first pass,