The Green Bay Packers will visit Soldier Field to take on the Chicago Bears in the 191st installment of the NFL's oldest rivalry on Sunday. After a heartbreaking loss in last year's NFC Conference Championship, the Packers enter the 2015 season as favorites to win the NFC North for a fifth consecutive year. The Bears, on the other hand, are under reconstruction after a last-place finish in the division. In this clash, John Fox's Bears will try to close the gap on the established dominance of Mike McCarthy's Packers.

Here are three keys to the game for both the Packers and the Bears.

PACKERS:

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1. Don't screw up on special teams

The Packers are pretty solid all around, but if they have one weakness it's special teams. After last season ended with a muffed onside-kick recovery, Packers head coach Mike McCarthy fired special teams coordinator Shawn Slocum and promoted Ron Zook to serve as his replacement. A hostile environment at Soldier Field will test the focus and discipline of Zook's unit from the get-go.

2. Start game (and season) fast

For the Packers to re-establish themselves as Super Bowl favorites, they must not miss a beat in the wake of Jordy Nelson's season-ending knee injury. Aaron Rodgers needs to keep the offense in motion with Randall Cobb, Davante Adams and third-round rookie Ty Montgomery -- as well as running back Eddie Lacy. Green Bay has started each of the past three seasons with a loss; the Packers will send a meaningful message with a quick and definitive takedown of the rival Bears in Week 1.

3. Capitalize in red zone

The Packers have one of the NFL's most potent offenses; the only place it sometimes slows down is in the red zone. The play-calling will be key in this area, so the pressure is on assistant coach Tom Clements (Mike McCarthy gave up offensive play-calling duties this offseason) to dial in the right routes and runs. Green Bay must double-down on the ground game when approaching the goal line -- this will open up options with the play-action fake.

BEARS:

1. Exploit passing matchups

Injuries may force the Bears to get creative in the passing game. Jay Cutler will be able to locate mismatches with running back Matt Forte and tight end Martellus Bennett against Green Bay's linebackers and safeties. Both Forte and Bennett can catch; they finished first and second on the team in terms of receptions last season with 192 between them.

2. Protect the ball

If the Bears turn the ball, they'll have a tough time keeping pace with Green Bay's super-powered offense. Cutler will have to make extra careful decisions, as he was the culprit of 24 turnovers last season (18 interceptions, six lost fumbles). If the ball bounces Chicago's way enough times, this game may not turn out to be the blowout everyone expects it to be.

3. Communicate on defense

It's not ideal to break a new defense in against the Packers' offense, but the Bears have no choice. Defensive coordinator Vic Fangio is building the Bears' first 3-4 defense, and it's surely going to have its kinks to work out after Week 1. All the Bears can do to make the most of the meantime is communicate with each other on defense and try to understand everyone's responsibility in the new system.