Whitner explains why Mason isn’t to blame for costly Purdy pick originally appeared on NBC Sports Bay Area

Brock Purdy’s late interception was the final blow in the 49ers’ 24-23 loss to the Arizona Cardinals on Sunday at Levi’s Stadium.

While the untrained eye might have pointed the finger at Jordan Mason for allowing a free rusher at Purdy, Donte Whitner explained why the running back isn’t to blame for San Francisco’s critical protection lapse.

“In Jordan Mason’s defense, right there they [Arizona] overloaded the blitz with five guys. They [49ers] had three offensive linemen and a back, and they [Cardinals] brought five guys, and they did a really good job of disguising it,” Whitner said on “49ers Postgame Live” after Sunday’s loss. “So I wouldn’t put that on Jordan Mason, because he is supposed to get the inner-most defender, and it still was an outside safety coming, and the tackle picked up the outside guy.

“I would say that it’s on Brock Purdy and that’s on Kyle Shanahan. He has to see that, he has to get rid of the football, or he has to avoid him and make him miss, but I don’t think that it’s on Jordan Mason.”

As Whitner noted, Mason picks up the defender with the shortest path to the quarterback, which is a cardinal rule in pass protection at any level of football.

Cardinals safety Jalen Thompson was able to explode through the B gap on the right side of San Francisco’s offensive line, striking Purdy while the quarterback was in his windup, leading to Arizona linebacker Kyzir White’s game-sealing interception.

Mason’s fourth-quarter red-zone fumble was a crucial mistake in the 49ers’ second-half collapse, but the running back should be free of blame for San Francisco’s final offensive play in Sunday’s loss.