Here are three things to watch from Miami's perspective:
Must-win situation: The Dolphins, despite losing five of their last six games, still believe they can make a run for the playoffs in the second half of the season. Both clubs have identical 4-5 records, and the loser of this game essentially will be eliminated from postseason contention in the AFC. The winner will be back at .500 with six games remaining.
Grounded attack: Miami rushed for a franchise-low 2 yards in last week's defeat to the previously winless Tampa Bay Buccaneers. The Dolphins must improve and have more balance on offense Sunday against the Chargers. Miami has a patchwork offensive line already down two starters due to Richie Incognito-Jonathan Martin controversy. Starting center Mike Pouncey also is questionable for the game with an unspecified illness, and the Dolphins lost backup offensive tackle Will Yeatman on Wednesday with a significant knee injury.
Slowing Rivers: Miami's 16th-ranked pass defense has a major test on its hands with San Diego quarterback Philip Rivers. The Chargers quarterback is putting up outstanding numbers. San Diego has the fourth-rated passing attack and a variety of weapons. Miami's secondary has been hit and miss this season. But this group must step up for the Dolphins to prevail. Players such as cornerback Brent Grimes and safety Reshad Jones have to make big plays defending the pass.