Robert Gauthier/Los Angeles Times

There is no denying that Jim Harbaugh is a great head coach. He completely changed the culture within the Los Angeles Chargers. However, the Los Angeles Chargers are becoming a fraudulent team.

Just three weeks ago, the Chargers took the field at SoFi Stadium on Monday Night Football with a record of 7-3. Winners of four straight games, the Chargers appeared to be real playoff and AFC contenders.

But since running back JK Dobbins suffered an injury on Monday Night Football against the Baltimore Ravens in Week 12 that put him on injured reserve, the Chargers have been floundering and losing their footing. The Chargers are 1-3 in their last four games, including a demoralizing 40-17 loss to the Tampa Bay Buccaneers last Sunday.

A big part of Harbaugh’s first season with the Chargers was relieving pressure on quarterback Justin Herbert. While that may help him, as he completed 367 pass attempts without an interception before Sunday, it also puts him behind other premier quarterbacks in the NFL who put up big numbers. Herbert has just 16 touchdown passes in 14 games and ranks 17th in the NFL with 2,959 passing yards.

Without Dobbins, the Chargers have difficulty running the ball. JK Dobbins leads the team in rushing with 766 yards. The next closest leader in rushing yards is Gus Edwards with 297 yards. Justin Herbert is third with 224 rushing yards.

The Chargers’ inability to run the ball could negatively impact their chances in the playoffs or even making the playoffs. Sure, the Chargers are 8-6 and have the No. 7 seed in the AFC playoffs, but there are no guarantees in the NFL.

Herbert is devastated. He injured his hamstring in Week 14 against Kansas City, and that could have impacted Sunday against the Buccaneers. Herbert threw for just 195 yards and was sacked three times in the Chargers’ loss. He has now been sacked 15 times in the Chargers’ last four games.

Interestingly, Herbert only had three games this year in which he completed 70 percent or more of his passes. Additionally, Herbert has only thrown for 300 yards in a game this season, and that was a loss at the Arizona Cardinals in Week 7. He is still struggling, with 38 sacks in 14 games this season. The entire purpose of Harbaugh’s arrival in Los Angeles was to exonerate Herbert. Herbert has thrown at least 30 passes in four of the Chargers’ last five games. Without Dobbins, the Chargers have lost confidence in their running game.

The Chargers have a good receiving corps. But which receiver other than Ladd McConkey do you trust the most? Only one other receiver has at least 40 receptions (Will Dissly) and only one other receiver has more than one touchdown (Quinten Johnston).

Defensively, the Chargers have struggled in the last five games. In the last three games in particular, the Chargers allowed 27, 30 and 40 points. This is a defense that prides itself on limiting the opponent in both moving the ball and putting points up the field. But over the last five games, we’ve seen the Cincinnati Bengals (452), Baltimore Ravens (389), Atlanta Falcons (350) and Buccaneers (506) move the ball up and down against the Chargers’ defense. They still lead the NFL in defense, but the Chargers only rank 14th in the NFL in yards allowed per game.

The Chargers have three games remaining: at home against the Denver Broncos on Thursday Night Football, at the New England Patriots in Week 17 and then at the Las Vegas Raiders in Week 18. Realistically, the Chargers should have at least 2 in their last game: 1 win three games, and 10-7 should come

them in the playoffs. But considering what we’ve seen in the Chargers’ last four games, there’s no guarantee that anything is realistic.

There are a lot of questions surrounding the Chargers right now. These questions didn’t exist four weeks ago when the Chargers were 7-3. Now at 8-6, are the Chargers the team we thought they were? There are signs that this team is fraudulent. Jim Harbaugh has a big challenge to get this Chargers team moving in the right direction toward the playoffs, if the Chargers get there.