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Third-year safety M.D. Jennings has had a rather difficult 2013 season. In fact, he's been so bad that it's officially time for the Green Bay Packers to replace Jennings with second-year safety Sean Richardson.

The Packers have had one of the worst defenses in the league this year. The main culprit for the defensive struggles has been the inability to stop the passing game.

On the year, the Packers are giving up an average of 252.9 passing yards per game, the 11th most in the NFL. The 26 touchdowns they've allowed through the air are the seventh most in the league and their nine interceptions are good enough for the third fewest through 14 games.

Simply put, Green Bay needs to improve its pass defense, and the way to start moving in that direction is to replace Jennings with Richardson at safety. Here's a look at why the Packers should make this decision.

The Struggles of M.D. Jennings

The following tweet from Ben Fennell of NFL Films basically sums up the Packers defense with Jennings on the field:

Opposing offenses are able to dominate Green Bay with Jennings in the secondary. Take a look at how poorly he's been graded by Pro Football Focus this season (subscription required):

M.D. Jennings PFF Grades Grade NFL Rank Pass Rushing -1.4 73rd Pass Coverage -5.8 74th Run 1.1 29th Overall -4.7 63rd Via Pro Football Focus

The only aspect of Jennings' game that is decent is his run support. However, his massive struggles throughout the rest of his game completely hide any good plays he might make against the run.

All of these poor statistics show up on the game film week after week. Here's a play from the Packers' Week 15 matchup against the Atlanta Falcons that shows Jennings' shortcomings perfectly.

As you can see in the picture below, the Packers are in a Cover 1 coverage scheme with Jennings playing the deep safety. That means he is the last line of defense between the Falcons and a touchdown.

Photo from NFL Game Rewind

The Falcons run wide receiver Drew Davis on a slant across the middle of the field. Safety Morgan Burnett fails to make a play on the ball originally, which sets up a one-on-one matchup between Davis and Jennings.

Photo from NFL Game Rewind

Unfortunately, Jennings completely misses the tackle and this allows Davis to walk into the end zone.

Photo from NFL Game Rewind

It's this type of inability to make a play when the Packers need one that should ultimately land Jennings on the bench for the remainder of the season.

The Solid Play of Sean Richardson

Since we started with a tweet from Ben Fennell of NFL Films, let's do the same with Richardson and see the difference in performance:

The most important thing to see here is the turnovers that the Packers created against the Dallas Cowboys with Richardson on the field. Also, Green Bay recorded two of its three sacks with Richardson in.

Let's take a look at a play against Atlanta that displays the difference between Richardson and Jennings. The play we'll look at is a run play to Jacquizz Rodgers. The first thing to notice in the picture below is how deep Richardson is when the ball is snapped.

Photo from NFL Game Rewind

However, Richardson explodes and is in position to make a play on Rodgers right at the line of scrimmage.

Photo from NFL Game Rewind

What makes this play so clutch for Richardson is the fact that there is so much open field behind him. If he doesn't make this tackle, Rodgers would likely pick up a huge chunk of yards.

Photo from NFL Game Rewind

Unlike Jennings, Richardson makes ideal contact with Rodgers and is able to bring him down. He stops a potentially large gain while showing off his instincts and sound fundamentals.

With the Packers controlling their own destiny to the playoffs they are going to need their defense to play solid football now more than ever. They can't afford missed tackles or blown coverage.

While Jennings isn't the lone problem with the Packers defense, he's certainly a big one. By replacing Jennings with Richardson the Packers would get an impact player in the secondary who isn't prone to making game-changing mistakes.

Now there still may be some talent in Jennings that the Packers haven't tapped into just yet; however, his poor showing on the field and his inability to make plays when Green Bay needs it is why it's time for Jennings to hit the bench and for Richardson to find himself in the starting lineup.