Getty Images

NFL Significantly expanded at the base against the blocks below the waist This is off season, and at the Chiefs-49ers game Saturday night, we got a look at just how important this change is.

In a play that would have seemed perfectly normal to anyone who hadn’t read the new rule, 49ers offensive lineman Corbin Kaufusi was trying to prevent the Chiefs’ safety. Will Parks on the outside term. Parks went low in an effort to avoid Kaufusi and make the intervention, and because parks hit Kaufusi low, parks were flagged for illegal low block, a 15-yard penalty.

Former NFL player Tim Ryan, who called on the telecast of the game, noted that for a smaller defensive linebacker trying to take on a larger offensive lineman, that makes it very difficult to beat the block.

“This is going to change the ambient running game and the screen game,” Ryan said. “Last year it wasn’t a penalty. This year it is. . . . get out of the way or get out.”

As former NFL referee Terry Macaulay wrote on Twitter about the dilemma of a defensive back if he can’t pull back from a much larger offensive line, “Not sure what he’s supposed to do. “

Defensive linebackers must find out what they are supposed to do, as the new rule could be a significant change in the way they do their jobs.