Buccaneers vs. Vikings: Three key matchups when the Buccaneers are on defense

The Tampa Bay Buccaneers have been nothing short of a total disappointment on defense this season, as they've been unable to stop any opposing offense despite bringing in a head coach known for his defensive prowess.

This weekend the Bucs will take on the Vikings, who have been struggling on offense as of late, and are struggling to find an identity without Adrian Peterson in the lineup. So how do the Bucs win against the Vikings when Minnesota has the ball? Here are three key matchups to watch.

Lavonte David versus Jerick McKinnon

The Vikings may not have Adrian Peterson, but they do have an exciting young athlete who is starting to settle into his new role as an NFL running back. Jerick McKinnon played quarterback and triple-option running back at Georgia Southern before posting ridiculous numbers at the NFL Combine and getting drafted by the Vikings.

He's not a complete running back yet, but he's working his way into the rotation every week, and has overtaken Matt Asiata as the lead back. McKinnon has a crazy combination of speed and strength, and will be a difficult player to chase down for the Tampa Bay defense.

That's where Lavonte David must shine, and track down the rookie whenever he's in space and looking to make a play. David is one of the few athletes on the Tampa Bay defense who can keep up with McKinnon, and that means he'll be as important as ever to the Bucs defense this weekend.

Michael Johnson versus Matt Kalil

Matt Kalil has been one of the worst left tackles in football this season (considerably worse than even the Bucs' Anthony Collins), but Michael Johnson and the Tampa Bay defensive ends have been equally disappointing so far this year. So which side of this matchup of letdowns this year will win out?

If the Bucs hope to win, they'll have to keep Teddy Bridgewater under pressure without blitzing, and that means Johnson must create consistent pressure from the defensive end spot. Getting a one-on-one matchup with a struggling left tackle makes that an easier task in theory, but Johnson must follow-through with a solid on-the-field performance against a tackle who is clearly capable of better than his 2014 performances so far.

The Buccaneers versus themselves

More important than any individual matchup this weekend will be the Bucs' ability to remain disciplined, play fundamentally sound football, and take advantage of Minnesota mistakes. Tampa Bay has been burnt by screens, misdirection plays, play action and end-around runs all season, and the Vikings have the playmakers to use any of those types of plays to torch the Bucs in Week 8.

Keeping contain on Teddy Bridgewater will be vital, especially if he's scrambling away from a pass rush, while tackling speedsters like McKinnon and Cordarrelle Patterson on the first try will be crucial in avoiding big plays.

The Bucs have committed countless unforced errors on defense this season, and cannot afford to continue to shoot themselves in the foot in what should be an easier matchup on defense than recent matchups have presented.