The NFL's most vicious rivalry is renewed this week as the Baltimore Ravens host the Pittsburgh Steelers. Ben Roethlisberger is hurt, but the Steelers are fighting for their playoff lives. They can't afford three consecutive losses.
These are three of the more underrated storylines this weekend:
Randall Cobb vs. Minnesota Vikings' defense
The Green Bay Packers have used Cobb as their own Cheesehead version of Percy Harvin, lining him out wide, in the slot and in the backfield. He leads Green Bay in receptions and has eight touchdowns. Cobb has been the most consistent weapon in Aaron Rodgers' arsenal.
The Vikings have the NFL's 13th-ranked pass defense. Cobb needs to be a high priority for Minnesota to pull off the upset.
Doug Martin vs. Denver Broncos' run defense
The Tampa Bay Buccaneers have won four of their last five games as the man with the worst nickname in sports found his groove. He has averaged 128.4 rushing yards in those games. The offense goes as he goes. Martin becomes even more valuable this week as Tampa Bay tries to run the ball, control the clock and keep Peyton Manning on the sideline.
The Broncos' run defense ranks No. 9 in the league and has allowed a 100-yard rusher only once in the last six weeks. The challenge is simple: Stop the Bucs' run game, and the likelihood of victory skyrockets.
Brandon Marshall vs. Seattle Seahawks' pass defense
Marshall remains the lone true threat in the Bears' passing game. He leads the team with 81 receptions for 1,017 yards and eight touchdowns. Running back Matt Forte's 27 catches is the second-most on the roster. Marshall basically is the passing game.
The Seahawks bring the No. 3 pass defense in the league, bolstered by cornerbacks Richard Sherman and Brandon Browner. At 6-foot-3 and 6-4, respectively, they have the size needed to compete with the physical Marshall (6-4, 230 pounds).
The advantage goes to Seattle if those corners can handle Marshall one-on-one and allow the front seven or eight to play aggressive in the box.
Follow Kareem Copeland on Twitter @kareemcopeland.