San Diego ? The San Diego Chargers don’t want to call their showdown with the Denver Broncos a must-win.

They certainly know it’s a can’t-lose game.

The Chargers were built up in preseason as a Super Bowl favorite, capable of wrapping up their fourth straight AFC West title. Denver certainly hasn’t been cooperating with that scenario, jumping to the division lead at 5-0 while watching the Chargers stumble to a 2-2 start.

An intense rivalry is renewed tonight at Qualcomm Stadium.

If the Broncos win, and don’t collapse the way they did at the end of last season, it could be hard for the Chargers to catch them.

So, no matter what the Chargers say, it’s a must-win.

“I don’t know that you can ever approach a game any other way,” quarterback Philip Rivers said. “Certainly the implications of this game are always big. Throw in the fact that we’re already two down, sure, I mean, it’s as big as a regular-season game gets.”

This is the first of three straight division game for the Bolts, who are coming off a bye that helped soothe the physical and mental pain of once again getting exposed physically by the defending Super Bowl champion Pittsburgh Steelers. San Diego fell behind, 28-0, and allowed 497 yards in a 38-28 loss at Pittsburgh.

The Chargers haven’t been able to run the ball or stop the run.

“I think mentally we understand what effect a win’s going to have and at the same time what effect a loss is going to have,” Rivers said.

The Broncos are coming off a 20-17 overtime victory over the New England Patriots, giving rookie coach Josh McDaniels a win against his mentor, Bill Belichick.

The Broncos have an impressive offense, run by Kyle Orton and featuring wide receiver Brandon Marshall and rookie running back Knowshon Moreno.