SAN DIEGO, CA - DECEMBER 20:  Head coach Dan Campbell of the Miami Dolphins stands on the field before playing the San Diego Chargers at Qualcomm Stadium on December 20, 2015 in San Diego, California.  (Photo by Todd Warshaw/Getty Images)

Most disappointing teams in 2015 NFL season

While some NFL teams are fighting for playoff spots, others are wondering what went wrong in 2015.

More was expected from these five teams this season.

Dolphins (5-9)

The Dolphins have been disappointment double-dippers in 2015.

They brought in Ndamukong Suh and added Jordan Cameron and Kenny Stills to the offense while putting their faith in Ryan Tannehill with a $96 million contract extension.

Then they started the season 1-3 and Joe Philbin was fired.

Dan Campbell came in and the Dolphins whipped the Titans 38-10 and the Texans 44-26 to get to .500. Campbell certainly was a more inspiring leader than Philbin, but some observers might have gone a little overboard.

There’s nothing like a trip to New England to bring the Dolphins back to reality. Four days after that win over the Texans, the Dolphins lost 36-7 at Gillette Stadium.

Defensive end Cameron Wake was lost for the season that night with a torn Achilles. He had four sacks against the Titans, two against the Texans and one against the Patriots before getting hurt.

Losing Wake didn’t help, but it also turns out the Dolphins are paying nearly $100 million for an average quarterback. Tannehill is 14th with 22 touchdown passes and 12th with 3,529 passing yards. His 87.3 passer rating places him outside the top 20 among starting quarterbacks.

The Dolphins showed how little it means to win the offseason, and Campbell probably will be coaching tight ends again next season.

Chargers (4-10)

The Chargers had a chance to take advantage of Peyton Manning’s advanced age and end the Broncos’ four-year reign over the AFC West.

Yet despite 4,287 passing yards from Philip Rivers, second in the league, the Chargers are likely going to finish last in the division.

Perhaps the Chargers’ inability to beat a Mike Vick-led Steelers team at home in Week 5 was the first sign of the disaster to come. After a 2-2 start, the Chargers lost 24-20 on Le’Veon Bell’s last-second touchdown run out of the wildcat.

That was the iceberg that sank the Chargers’ season, the first of six straight losses. The Chargers already were 2-5 when Keenan Allen was lost for the season with a lacerated kidney.

The Chargers are producing 377.8 yards per game, sixth in the NFL, but they don’t put yards on the scoreboard. They’re scoring 20 points per game, 25th in the league. The Chargers looked like a team mailing it in with three points in three out of four games before bidding a possible farewell to their home fans and beating the Dolphins 30-14 Sunday.

Lions (5-9)

To make the playoffs in back-to-back years for the first time since 1995, the Lions were going to have to weather a challenging early-season schedule. Four of the first five teams they faced are likely headed toward the playoffs, but the Lions couldn’t get a single win in that stretch and started 0-5.

They showed they’re not as bad a team as they looked early in the season when they won three straight to get to 4-7, including their first win at Green Bay since 1991. They would have won at least four in a row, however, if they had just put someone on Richard Rodgers on the final play against the Packers at Detroit.

Perhaps the continued momentum would have kept them from losing at St. Louis the following week and they’d still have a shot at a playoff berth. Instead, they’re guaranteed their 13th losing season in the last 15 years.

Colts (6-8)

After finishing 11-5 in three straight seasons and advancing a step closer to the Super Bowl in each of those years, a .500 or worse season is a disappointment.

The Colts have been without Andrew Luck for half the season, but they’re only 2-5 in the games that they’ve had Luck.

Perhaps that 20-7, Week 2 home loss to the Jets is understandable, but that 27-21, Week 7 home loss to the Saints is hard to swallow.

It looked like Matt Hasselbeck was going to rescue the Colts. He won his first four games as a starter and the Colts were 6-5 going into December, but they’ve lost three straight including clunkers at Pittsburgh (45-10) and Jacksonville (51-16).

On Sunday, the Colts allowed the Texans to win at Indianapolis for the first time in their history. To avoid their first non-playoff season since Curtis Painter was their quarterback, the Colts have to win at least one of their final two games (at Miami and home to Tennessee) and hope the Texans lose at Tennessee Sunday and at home to Jacksonville in Week 17.

Ravens (4-10)

This will be the Ravens’ first losing season since the John Harbaugh-Joe Flacco Era began in 2008.

Sure, the Ravens have been beset by injuries. They lost Terrell Suggs in the season opener. They still had Joe Flacco, Justin Forsett and Steve Smith Sr., however, throughout their 1-6 start.

After starting 0-3, they won 23-20 in overtime at Pittsburgh against Mike Vick on a night when now-unemployed Josh Scobee missed two field goals in the final two and a half minutes. They followed that up with a home loss to the Browns and a loss at San Francisco. Those teams have a combined 7-21 record. Those were winnable games even without Suggs.

Smith went down in Week 8 and Flacco and Forsett were lost in Week 11. The Ravens managed wins against the Rams and Browns, but have lost three straight and are in danger of their worst season since they went 4-12 in 1996, their inaugural campaign.