Greatness cannot be found at the bottom of a Pringles can.

To that, the Chargers can attest. After feasting on Twinkies and cream pies for most of last season, the Chargers found themselves ill-prepared to handle the blast furnace intensity of the NFL playoffs. Imagine training for a triathlon with 12-hour sessions in the recliner, watching Oprah and eating bonbons.

That, in effect, is what the Chargers did last year in compiling a 14-2 record against an assortment of cupcakes and creampuffs. Then came their playoff pratfall against the New England Patriots. In retrospect, the loss -- littered with foolish penalties, dumb mistakes and dubious coaching moves -- wasn't so much stunning as it was preordained.

This season, there hasn't been nearly as many empty calories on the schedule. It's no coincidence that there have been more losses. The Chargers are 7-5 entering Sunday's game at Tennessee.

The unbeaten New England Patriots throttled the Chargers in Week 2, and that was followed by another road loss to NFC powerhouse Green Bay. Jacksonville and Minnesota, both likely playoff teams, also beat the visiting Chargers, who are just 2-4 on the road.

The Chargers have defeated just one team with a winning record this season. That 23-21 "triumph" over the 10-2 Indianapolis Colts required a stunning last-second miss of a chip-shot field goal by Mr. Clutch himself, golden-toed Adam Vinatieri. Chargers players were more embarrassed than energized by the outcome. Fan reaction ranged, bizarre for a victory, from upset to outraged to "diablo" hot.

Last Sunday's 24-10 win over the Kansas City Chiefs was the Chargers' sixth win in eight games. But it was hardly emphatic. Playing against a team with a second-string quarterback, third-string running back and dwindling fan base, the Chargers didn't lead until the third quarter. They needed two second-half highlight-reel touchdown runs from LaDainian Tomlinson to send what was left of the sparse crowd shuffling to the parking lot.

Sunday's game against the Titans marks the Chargers' last chance this season to secure a road victory over a winning team. For the Chargers, it's the sort of game they've rarely played -- and most often lost -- over the last two seasons.

The Titans are 7-5 and perched atop the playoff bubble. They play in the AFC South, a division that also includes the defending Super Bowl champion Colts and 8-4 Jaguars. Tennessee features a heavily credentialed quarterback (Vince Young) and highly respected coach (Jeff Fisher).

"I think it is a good opportunity, especially playing a team that's in the playoff hunt," Tomlinson told the North County Times on Wednesday. "It can do so much for us confidence-wise if we can win this game at their place, a playoff team. It will go a long way for later on for us."

Beat this team, on the road in December, and just maybe the Chargers will be an inch closer to winning their first playoff game since 1994. Of the seven Super Bowl winners this decade, only last year's Indianapolis Colts had a losing record in their final five games. The only other team that went worse than 4-1 was the 2002 Tampa Bay Buccaneers, who went 3-2 down the stretch.

"We're just trying to win the division and have high enough numbers to get (in the playoffs)," Chargers general manager A.J. Smith said. "Beyond that, you'd like to be playing real consistent football in the last month, particularly in the last three weeks."

Smith pointed out that the Chargers were six points away from an unbeaten season last year. Then he added this: "All of that means nothing once you get in the postseason. Nothing. That challenge starts all over again. That's the beauty of it."

After Sunday's win over the Chiefs, Chargers players were asked about building momentum for the playoffs. Perhaps realizing they had done nothing more than kick sand on a junior varsity squad, they kept the playoff talk to a minimum.

"Two losses and we're right back where we started," Tomlinson said.

The Titans represent the last meaty opponent on the Chargers' schedule. Home games against slumping Detroit and Denver are followed by the season finale at perennially horrific Oakland. Not exactly a Murderers' Row of NFL heavyweights.

The Titans or Jaguars are the type of team the Chargers likely would play at home in the postseason. Can they beat them then? Can they beat them now?

How good is this Chargers' team? Twelve games into the season, and still no one knows.

"I think this is a good week to really find out for sure against a playoff-caliber opponent at their place," quarterback Philip Rivers told reporters Wednesday. "I would expect a playoff atmosphere. And these are the kind of games, again, we haven't won earlier in the year, that we need to go in there and a win."

All those wins against all those patsies last year did nothing but install an inflated sense of security. Maybe that beatdown by the Patriots this season was a good thing.

And nothing will deflate overblown egos faster than watching an opposing running back (Minnesota's Adrian Peterson) do a Forrest Gump on your defense. Trying to stop quarterbacks named Brady, Manning and Favre isn't a bad way to prep for the postseason, either.

"I'd take 8-8 and win that first (playoff) game," Chargers president Dean Spanos said before the season. "That's better than 14-2 and out."

Say what you will about Spanos' guidance of an often-wayward franchise, but he's right about that. In the end, the cupcake diet leaves you feeling empty.

Fortunately for the Chargers, the Titans will serve a hearty meal on Sunday. We'll find out just how good, how hungry, they are.

For one week, at least, dessert is not on the menu.

Contact sports editor Loren Nelson at (760) 740-3551 or lnelson@nctimes.com.