Heading into Week 12 of the 2019 NFL season, the Green Bay Packers are looking to prove once again that they are a legitimate Super Bowl contender. After starting the season 8-2, the Packers are coming off of their bye week and are at full health this week. The Packers are facing the best team in the NFC, as the 49ers are 9-1 on the season.

Aaron Rodgers and Matt LaFleur will need their offense to be firing on all cylinders, but the defense will have to step up as well. Green Bay will need to play one of their best games of the season to pull out this win.

All of that being said, let's dive in and take a look at two major X-Factors who must step up for the Packers this week against San Francisco.

Darnell Savage Jr., Safety

On the defensive side of the football, the Packers are going to need their rookie safety to have a good game. Obviously, the 49ers feast on the ground with a handful of running backs who can play at any time. Savage is a safety, but he is fast and will need to make some big tackles and might be used in the blitzing game by defensive coordinator Mike Pettine.

Jimmy Garoppolo is also a quarterback that defenses can take advantage of in some games. Green Bay has a solid pass rush and that could force Garoppolo to make a few mistakes. Savage is capable of making plays on the football as well and will have an opportunity or two this week.

Jamaal Williams, Running Back

Green Bay is well-known for rising star running back Aaron Jones. Jamaal Williams is the backup running back, but he has a massive role as a receiver out of the backfield and has made quite a few big plays on the ground as well. He must step up this week in both roles.

Aaron Rodgers is playing at an MVP-caliber level, but he will need some pressure taken off of his arm. If the Packers can get both Jones and Williams going like they have in quite a few games so far this season, the Packers are going to be tough to stop. Williams must step up and be a difference maker this week.