Then came a four-game winning streak to cap the season. As well as an epic collapse by the Broncos, who were in first place every week except after the final game.
That's why many think the Chargers have a good shot of advancing deep into the tournament for the second straight year.
Despite having a prime opportunity to fold when they were 4-8, the Chargers kept fighting. So the speculation is that if they were able to survive and dig out of that hole, the playoffs are almost like playing with house money.
QB Philip Rivers
"Philip is playing great football right now. He's playing like an MVP and hopefully it carries into next Saturday," linebacker Stephen Cooper said.
That the Chargers are still alive is amazing. But it also lends credence to what coach Norv Turner has preached since taking over for Marty Schottenheimer before last season: be playing your best football when the stakes are the highest.
The Chargers have done that, by extending their winning streak in December to 14 games.
"It's critical that you keep improving," Turner said. "I said this, and it's hard to say it when you lose close games like we did.
"We lost a one-point game at Pittsburgh. There are some other people who have lost close games, very low-scoring games there. Some pretty good teams have. We lost a three-point game to Indy. They're the hottest team in football right now. They've won nine straight. I said after the game, it was a lot like our playoff game back there except they won it and we didn't.
"When you're losing close games or you're not winning and you talk about players improving, I'm not sure you guys buy it but I see it and I saw it. (Defensive back) Paul Oliver is a great example. There are a bunch of guys. Stephen Cooper, we assume that he was just plugged back in and was ready to go. He's improved a great deal. He's playing his best football of his career."
But when players are ascending and the team is descending, it's tough to wrap your arms around the idea that better days are ahead.
"You see it happening, then you need it to show up in wins," Turner said. "That's what it's done over the last month, but we have a lot of players I think that are playing their best football of their career. That's important. It's obviously what we shoot for in terms of going forward."
RB LaDainian Tomlinson
"We're getting ready to play a team that has a lot of guys that are playing their best football of their career or the best football they've played this year," Turner said.
Still, the Chargers have to feel as if they have been given a reprieve. It wasn't long ago the players were being called underachievers, LaDainian Tomlinson was believed to be washed up, the defense couldn't overcome the loss of All-Pro linebacker Shawne Merriman and Turner wasn't suited to coach a Pop Warner squad, let alone the so-called most talented team in the NFL.
That's why Tomlinson points to this playoff trip as his most rewarding.
"I would say so," he said. "There was a point there where you were really starting to wonder if you were going to get in because Denver just had to win one game.
"Every week you were hoping. 'Man I hope they don't win. I hope they don't win.' When it came down to this last game of us playing Denver, at that point we felt like we were going to get in. I don't think there was any doubt in our mind that we would win that game."
But there was plenty of doubt - and doubters - before the calendar flipped to December. That's when the Chargers' persona switches from being disappointed to dangerous.
While the road the Chargers took to the playoffs had its share of potholes, they at least have reached their destination.
"It's not ideal but we'll take it," Tomlinson said. "It's a pretty strange season, isn't it? But it's good to be in this position, no doubt. To say that you're division champs and to be going to the playoffs and hosting a playoff game, that's a great feeling for us."
SERIES HISTORY: 26th meeting. The Chargers lead the series 15-10, and the teams are tied 1-1 in postseason matchups. The Chargers fell to the Colts in the regular season this year at home, 23-20. But last season, the Chargers upset the host Colts in a divisional playoff game, 28-24. The Chargers pulled off the unlikely victory despite QB Philip Rivers and RB LaDainian Tomlinson not playing down the stretch because of knee injuries.
LB Stephen Cooper
--RB LaDainian Tomlinson said it's the Colts' defensive speed which impresses him the most. "I know they're a team that relies on their quickness and speed," he said. "Obviously Bob Sanders leads that group as far as the physical aspect and getting those guys ready to go. I think they cause a lot of turnovers because of their speed and a lot of the stuff that they do and force you into making turnovers. That's one thing that we don't want to do is turn the ball over and give that offense with Peyton Manning a short field or an easy score."
--TE Antonio Gates was discussing before the regular-season finale how he was fit for the first time in a year. Then he turns his ankle in the win over the Broncos. "I was just talking about that, about how I was getting healthy," Gates said. "You could see it coming." Gates might have jinxed himself with such chatter. "I might have," he said. "But this is just a little ankle sprain. I played with the toe (injury). After that, this is like having the flu or something. You know I'm going to be out there (Saturday night)."
--Turner said he made examples of two future Hall of Famers who'll play on Saturday - Tomlinson and Manning. "I talked to our team about L.T.," Turner said. "And you look at (him passing) Marcus Allen for career touchdowns. He's gone eight years straight with 1,000 yards, with 50 catches. That's hard to do. Same thing with Peyton. You look at what he has done over an extended period of time. Those guys set a high standard for all young players."
--WR Malcom Floyd continues to work and could play Saturday after missing the past two games with a collapsed lung. "Once they took the tube out, I didn't feel any pain or anything of that nature," Floyd said. "I'm really anxious just to be a part of this winning streak that we're on. Floyd had five-catch games against the Atlanta Falcons and the Chiefs; he was injured in the Chiefs game. "I just hope I don't get out there and ruin the mojo," he said about the Chargers recent offensive excellence.
--QB Philip Rivers is amazed the Colts have allowed but six scoring passes this year. Rivers has 34, in setting the Chargers' team record this year; he had two against the Colts in their regular-season game. "That's crazy," Rivers said. "They're so simple in their scheme. They don't do a bunch of things. But they do it so well. They have those two pass rushers (Dwight Freeney and Robert Mathis) and Bob Sanders in there flying around."
--Indianapolis K Adam Vinatieri is clutch, proving it when hitting a pair of Super Bowl-clinching field goals and he made a 50-yarder as time expired to beat the Chargers in the regular season. But he hasn't been great at Qualcomm Stadium, however, hitting 4-of-7 field goals. He missed a 29-yard attempt that could've won a 2007 regular-season game against the Chargers.
--LB Freddy Keiaho was teammates with Chargers WR Kassim Osgood and LB Antwan Applewhite at San Diego State.
--The Chargers have allowed Peyton Manning to throw for 10 touchdowns against them. That said, they have intercepted him 12 times.
--Rod Perry, the Colts' special assistant to defense, was the Chargers' secondary coach from 1997-2001.
BY THE NUMBERS: 4 - Trips to the postseason for the Chargers in the last five years. From 1996-2003 the team didn't make the playoffs.
QUOTE TO NOTE: "Yeah, I think so. I think over the last two weeks we have played great football, as good as we've played the last two years. Scoring 41 points in Tampa and then turning around and scoring 52, that's pretty good for the National Football League. This is not college, now. (Where) you're Oklahoma scoring 60 points the last five games, but it's pretty good to be in the NFL." -- RB LaDainian Tomlinson on if the Chargers are hitting their stride.
STRATEGY AND PERSONNEL
Look for tight end Brandon Manumaleuna to see plenty of action, but not as a pass catcher. Manumaleuna will spend part of his day attached to LT Marcus McNeill's hip to help out on slowing Dwight Freeney. Although if Antonio Gates is slowed or aggravates his sprained ankle, Manumaleuna could be asked to do more than block.
WR Vincent Jackson
--OLB Shaun Phillips not only leads the teams with 71/2 sacks but with 15 tackles for a loss as well.
--P Mike Scifres set a team record with a net punting average of 40.9 yards. He was third in the league in that category.
--LS David Binn is in his 15th season and will play in his team record 249th Chargers game on Saturday night.
--QB Philip Rivers has led the Chargers to three AFC West titles in his three years as a starter.
--CB Antonio Cromartie has four of his 14 career interceptions, including the playoffs, against the Colts' Peyton Manning. Cromartie has two interceptions this season.
GAME PLAN: The Chargers should lean on their running game for a few reasons. The running game has been cooking of late with the offensive line playing their best football of the year. But getting the ground attack in full gear gobbles up yards and the clock, which keeps Manning and his offense off the field. The Colts have allowed but six touchdown passes this year. That speaks to a secondary which includes Bob Sanders and to a stout pass rush. The key here is the health of Tomlinson. He suffered a strained groin in the win over the Broncos and could be at less than full strength.
MATCHUPS TO WATCH:
Chargers passing game, led by Rivers, the NFL's leading quarterback regarding rating and touchdown passes, vs. a Colts pass defense which has Dwight Freeney and Robert Mathis coming off the edges.
Rivers has been keen of getting rid of the ball lately, as the turnovers which had plagued him in the midseason have dwindled. He has a new favorite toy in Vincent Jackson, who has surpassed Chris Chambers as the team's top wide out. But the pass blocking is going to have to give Rivers the time until Jackson can complete his downfield moves.
Chargers pass defense, which hasn't been getting at quarterbacks lately, vs. the Colts passing offense with a hot Manning.
The Chargers, to have any hope of disrupting the Colts' passing game, is going to have to supply some heat on Manning. But the Chargers have but one sack in the last three games and sacked Manning but once when playing him in November. Manning has completed 90-of-110 passes in his last four games and is the main reason the Colts have won nine straight. Pay attention to the Colts' Dallas Clark as tight ends have killed the Chargers all season long. But the big thing is not letting Manning set his feet.
Chargers running game, with a nicked-up LaDainian Tomlinson against a Colts run defense, which is allowing 123 yards per game.
The Chargers won't be at full strength with Tomlinson slowed by a strained groin. That means the Chargers will likely have to lean more on Darren Sproles and rookie fullback Jacob Hester. While it's not technically a run, look for Sproles to supply his "running" yards via swing passes out of the backfield to get him into space. The Chargers' run blocking has been solid lately. The Chargers need to have positive yards on early downs or Rivers will be forced into third-and-longs. If that's the case, DEs Dwight Freeney and Robert Mathis can get after Rivers with vengeance.
--RB LaDainian Tomlinson (groin) didn't practice on Wednesday but will go Thursday. Still, he likely won't be at 100 percent Saturday. Look for Darren Sproles and Jacob Hester to get some additional playing time.
--TE Antonio Gates (ankle) didn't practice but will on Thursday. Unless there is a setback he will go on Saturday.
--WR Malcom Floyd (lung) worked again and could be activated on Saturday after missing two straight games.
--LB Brandon Siler (foot) didn't practice and he could be down this week.