Chargers (1-4) at Raiders (2-3)

When: 1:25 p.m. Sunday TV: Radio: 95.7, 98.5, 102.9 Spotlight on: Derek Carr. The Raiders are 14-5 in Carr’s starts since the beginning of last season — and 0-3 when another quarterback starts (including the playoffs). Still, the offense was sputtering even before Carr went down with a transverse process fracture in his back Oct. 1 against Denver. Now he returns in a suddenly urgent game, with the Raiders desperately trying to avoid a four-game losing streak heading into Thursday night’s matchup with mighty Kansas City. Is Carr mobile enough to avoid the pass rush? Is he sharp enough to pump life into his sagging team? Injury notes: Chargers — OT Joe Barksdale (foot), LB Jatavis Brown (ankle), RB Branden Oliver (hamstring) and WR Mike Williams (back) are questionable. Raiders — CB Gareon Conley (shin), LB Marquel Lee (ankle) and FB Jamize Olawale (concussion) are out. CB David Amerson (shoulder), LB Cory James (knee) and RB DeAndre Washington (hamstring) are questionable.

THE BIG 3

Air quality has been a concern all week in the region, given drifting smoke from the deadly North Bay wildfires. Some Raiders players wore surgical face masks during practice Thursday. Air quality seemed to improve in the East Bay on Friday and Saturday, but that could change if the wind shifts. Even if Sunday’s game remains in Oakland, as expected, the smoky air could affect players, especially as they tire in the second half.

The Raiders already had question marks at linebacker and in the secondary before they endured a wave of injuries at those positions. That leaves them vulnerable to a Chargers pass offense ranked No. 6 in the NFL, at nearly 267 yards per game. Longtime nemesis Philip Rivers is still flinging passes at age 35, and he has a reliable target in Cal alum Keenan Allen. Rivers figures to focus on Raiders cornerback Sean Smith, who continues to struggle in coverage.

Oakland’s offensive line, after poor outings against Washington and Denver, showed progress in sparking the running game a bit in last week’s loss to Baltimore. Now the Raiders face a stout challenge in creating room for running back Marshawn Lynch and protecting Carr from a spirited Chargers pass rush. Los Angeles has 17 sacks, tied for fourth in the league; Melvin Ingram and Joey Bosa lead the way.