The New England Patriots enter Monday's night game against the Kansas City Chiefs looking to stay atop the AFC East. Kansas City's offense will be reinvigorated with the return of star running back Jamaal Charles, and the Chiefs need a win or risk falling behind in the AFC West race.
Here's what you need to know:
How will Alex Smith penetrate the Patriots' defense?

New England strengthened its secondary in the offseason, adding shutdown corner Darrelle Revis and Seahawks cast-off Brandon Browner. The duo have paid dividends for the Patriots already, as the team was tied for the NFL lead in interceptions prior to Thursday's game between the New York Giants and Washington Redskins.
The Patriots are forcing turnovers in a number of ways. Defensive end Chandler Jones is causing havoc at the line, deflecting two passes in a Week 3 win over the Raiders. The Chiefs have given up 11 sacks through three games, the second-worst total in the league. Jones could have a field day if the Chiefs' line continues to struggle. Moreover, New England's trio of linebackers excel in coverage, and will limit Alex Smith's ability to find his safety valves.
Smith has been erratic through three games, throwing four touchdowns against three interceptions. The Chiefs will be less predictable with Charles back in the lineup but if the Patriots take an early lead and force Smith to run a pass-heavy offense, Kansas City could be in trouble.
Will the Patriots' offensive line keep Tom Brady upright?

The Patriots have surrendered seven sacks through three games, and Tom Brady is certainly feeling the pressure. Brady has completed a mere 58.8 percent of his passes so far, while throwing for three touchdowns. While reports of his demise are still unfounded, Brady has been rattled when forced out of the pocket. Nonetheless, the Patriots star will try to take advantage of a Chiefs' secondary that will be without safety Eric Berry.
Kansas City may be the ideal team to square off against an erratic New England offensive line. The Chiefs have recorded nine sacks, fifth most in the league. Nose tackle Dontari Poe is leading the charge, dominating the Miami Dolphins in Week 3 with 1.5 sacks and a pass deflection. Poe's rare breed of athleticism will give the Patriots fits.
The many dimensions of Jamaal Charles

Charles' presence alone makes the Chiefs' offense less predictable. With Charles back in the lineup, the Patriots have to account for him at all times. While the Patriots' linebackers have been excellent in coverage, none of them can catch Charles in traffic.
Knile Davis was excellent with Charles out, and the Chiefs could keep the Patriots off balance by utilizing both backs. However, Charles was the team's top rusher and receiver last season and even if he's not fully recovered from an ankle injury, the Patriots' defense must account for his presence.