Brock Purdy may have cost himself some serious money this season. He wasn't bad, but he wasn't good, either. He was remarkably mediocre. And when the game was on the line in the second half, he was a liability.

Head coach Kyle Shanahan told reporters Thursday that Purdy will not play Week 18 against the Arizona Cardinals. Purdy suffered a right elbow contusion with nerve inflammation in San Francisco's 40-34 loss to the Detroit Lions on "Monday Night Football."

GM John Lynch sheds light on Brock Purdy's injury status, providing an update on his recovery as the team prepares for a critical offseason.