Chargers at Steelers -- Week 14

Where: Heinz Field, Pittsburgh (grass, outdoors)

When: Sunday, 1 p.m. (CBS)

Spread: Pittsburgh by 7.5

Weather: Light rain possible, with temperatures forecast in low 50s

Records: Chargers (4-8, AFC West 3-2); Steelers (7-5, AFC North 2-2)

Past results: Two most recent meetings -- Oct. 4, 2009: Steelers 38, Chargers 28.  Jan. 11, 2009: Steelers 35, Chargers 24 (AFC Divisional playoffs). Series record: Steelers lead 21-6 and are 14-0 in regular-season games in Pittsburgh.

What matters: These are two teams headed on divergent paths. The Chargers have lost four in succession and may well be getting their coach and general manager fired. The Steelers are getting back franchise quarterback Ben Roethlisberger from a shoulder injury and perhaps got their mojo back with a 23-20, come-from-behind victory against the arch-nemesis Ravens in Baltimore last week.

Who matters: The draft class reunion of 2004 continues. No. 11 overall Roethlisberger holds an upper hand on No. 4 Philip Rivers in a number of ways, most telling being the three Super Bowl appearances (two of them victories) and 3-0 head-to-head record. Last month, Roethlisberger beat No. 1 Eli Manning in their latest draft-class confrontation to take a 2-1 lead against him.

Key matchups: Third-team offensive tackle Kelvin Beachum, a rookie selected near the draft's end last spring -- and as a guard-center, no less -- must maintain his stellar pass protection and decent run blocking. Doesn't matter which Chargers he faces, but after the likes of Baltimore's Terrell Suggs and Paul Kruger he will be expected to perform at that standard. Second-year cornerbacks Cortez Allen and Curtis Brown, who ascended one rung from nickel and dime backs after Ike Taylor's foot injury, must keep Rivers frustrated and looking from the pocket as they cover San Diego's lanky receivers.

Injuries of note: Roethlisberger returns after a three-game absence. Linebacker LaMarr Woodley (ankle) and Taylor (foot) -- after leading all NFL cornerbacks with 135 consecutive starts -- are out. Safety Ryan Clark (hip) practiced Friday after two days on the sidelines. And fullback Will Johnson must pass concussion protocols before being able to play.

Inside stuff: The Steelers' defense historically puts the clamps on Rivers for a half or three quarters, then allows him to make the game closer in the end. But this season, the NFL's stingiest unit has a streak going -- eight games in a row allowing no more than 20 points, and they've only permitted 177 yards net passing or fewer in those games. 

Connections: The one meaningful Chargers connection to the Steelers and their fandom is the 1994 AFC Championship game in Three Rivers Stadium. In the end, Chargers linebacker Dennis Gibson knocked down a pass in the end zone intended  for running back Barry Foster and thrown by the quarterback who one year later played his final Steelers game in a SuperBowl XXX defeat, Neil O'Donnell. Utter any of those names aloud, and it would send most Steelers fans who are over 35 into apoplexy.

Stat you should know: Three meetings ago, in 2008, the Steelers beat the Chargers at Heinz Field by the first 11-10 final score in NFL history. . . Shaun Suisham has converted 13 field goals in succession and missed just once in 24 attempts this season.

Prediction: Steelers 24, Chargers 17

Follow Steelers reporter Chuck Finder on Twitter @CBSSteelers and @cfinder.