With their season hanging in the balance, the San Diego Chargers were able to avoid a bitter case of deja vu, turning away the Kansas City Chiefs’ two-point conversion attempt in the final minute to seal Sunday’s 20-19 victory over their rival in the underachieving AFC West. The thrilling win helped head coach Norv Turner exact revenge on the only team that beat him at Qualcomm Stadium a year ago, but the performance was far from encouraging. The Chargers struggled to find their form, almost letting a team that is 1-17 in its last 18 games beat them on their home field for the second straight year. The victory helped San Diego keep pace with division-leading Denver, but provided no reason to believe the Chargers are beginning to approach the Super Bowl caliber form that was expected during the preseason.

San Diego’s fundamental problem presented itself early in the NFL season when it became apparent that linebacker Shawne Merriman just wasn’t the same player with his damaged knee ligaments. After doing his best to play during the season opener against the Carolina Panthers, Merriman was immediately placed on injured reserve and ruled out for the season. His absence from the Chargers defense has taken nearly all the bite out of a unit that forced a league-leading 47 turnovers last year. It was a unit that while consistently surrendering yards in bunches, could always be counted on for a game-changing play. Just ask Super Bowl XLI MVP Peyton Manning, who threw eight interceptions in two games against San Diego last year. Merriman’s presence as a dominant speed rusher in San Diego’s 3-4 defense allowed him to get to the quarterback repeatedly, which in turn created big plays for the defense. In many ways, San Diego became too reliant on forcing turnovers and didn’t focus on becoming a stifling unit that could shut teams down. Now without Merriman, the Chargers have forced only 10 turnovers for the year and are 26th in total yards allowed. The ferocious pass rush from last year is nonexistent and allows opposing quarterbacks to pick apart the Chargers at will. It has gotten so bad that defensive coordinator Ted Cottrell has been fired. This has simply put too much pressure on the offense, which is actually playing very well.

The offense is holding its own mainly because Phillip Rivers has developed into one of the league’s elite quarterbacks. It may be hard to believe but Rivers leads the NFL in touchdown passes (21), is second in quarterback rating (106.3) and owns a 31-13 career record as a starter. Rivers has endured a ton of criticism and will never be able to escape Eli Manning’s enormous shadow, but the fifth-year quarterback has carried himself tremendously. The 27-year-old pro is still rough around the edges and is prone to forcing the action at times, but he has handled everything that has been thrown at him in stride. Running back LaDainian Tomlinson has been nowhere near his usual self this year — the turf toe injury simply makes him less explosive — and the offensive line has essentially been an assorted group of misfits, but it has done little to slow down the passing game. All year long, Rivers has been the leader of the offense, a post that was previously held by LT, and is the biggest reason San Diego is still in this thing with seven weeks to go.

Despite a mediocre 4-5 record and no semblance of effectiveness from their defense, the Chargers still have all of their goals in sight. San Diego may stare up at the Broncos in the standings, but the AFC West title could be on the line when they face each other at Qualcomm Stadium in a season-ending showdown on Dec. 28. Denver has regressed severely from a strong start, mostly because of a defense that has become worse than San Diego’s, and is ripe for a potential meltdown in the stretch run.

The Chargers don’t need to look far for motivation. At this point last year, the Chargers were in a similarly frustrating position at 5-5, but managed to find their groove in time to carry an eight-game winning streak to the AFC Championship Game. Matching that feat will be much more difficult, especially without Merriman and upcoming games against the Steelers, Colts and Falcons. With little margin for error, there is no more time for the Chargers to sleepwalk and go through the motions during their games. An inspiring performance is the only thing that will suffice on Sunday in Pittsburgh.