Mike Riley can laugh about it today – back then his starting quarterback fought against his teammate.

Riley, the Chargers’ head coach at the time, recalled that the team was on its way to its fourth consecutive loss. The Chargers failed to score a touchdown in a road game against the Oakland Raiders. Chargers safety Michael Dumas, whom Riley called “one of the toughest guys ever,” told the team’s quarterback about the problems on offense.

Jim Harbaugh was insulted. The quarterback pressed his face guard against Dumas’ and linebacker Junior Seau pulled them apart. It didn’t end on the field.

“When they got to the locker room, they were already really into the fight,” Riley said. “Jim didn’t let it get him down.”

Nearly three decades after being the manic-driven quarterback who wasn’t afraid to compete with his defensive teammates, Harbaugh brings that same passion to the franchise as head coach.

The player once known as “Captain Comeback” due to his dramatic playoff victories with the Indianapolis Colts will look to orchestrate another defeat for an organization that hasn’t won a playoff game since 2018.

Anyone who watched Harbaugh during his playing days knows that his rare blend of competitiveness, authenticity and empathy makes him ideally suited to accomplish that feat starting in Sunday’s season opener against the Oakland Raiders, which begins at 1:05 p.m. at SoFi Stadium.

“He wants to win more than anyone, and he will,” said former Chargers quarterback Ryan Leaf. “He’s going to win. I just thought that was the best fit because he’s going to do what’s best for the team to win. … That’s exactly what the Chargers needed.”

Harbaugh, a former Heisman Trophy finalist at Michigan, threw the final passes of his 15-year NFL career with the Chargers. In two seasons with the Chargers, Harbaugh was 6-11 as a starting quarterback.

When he joined the team in 1999, the Chargers needed a seasoned veteran to mentor Leaf. Harbaugh, then in his 13th professional season, didn’t just coach the former No. 2 pick.

During the offseason, Riley would occasionally look out his office window, which overlooked the practice fields as the rookies began training. When he looked closer, he saw a veteran in the group.

“Jim was totally focused on preparing for the season, for the game, whatever it was. He always wanted to do everything he could to be ready,” Riley said. “Then in the games he was the ultimate competitor.”

Even in a league full of ambitious players in the world, Harbaugh is “the most ambitious person you’ve ever met,” Leaf said.

It wasn’t just on the field. During the 2000 season, Chargers quarterbacks Leaf, Harbaugh and Moses Moreno spent their weekly off days playing golf together. They took turns choosing the course, and Leaf noticed a pattern in Harbaugh’s choices. He just didn’t want to play on the best courses. Looking for an advantage, Harbaugh would pick the courses that specifically suited his swing.

“He was like Michael Jordan,” Leaf said, referring to the basketball legend’s role in designing his private golf course in Florida to suit his style of play.

Harbaugh’s commitment to taking advantage of every opportunity has also translated to his famous attention to detail as a coach. Players are instructed to wear shoes — not slides or flip-flops — during meetings, when they have to get up and walk during a game, and in the weight room, they line up their shoes in a precise order.

With his trademark “enthusiasm like no other,” Harbaugh organized a record-breaking team photo day, with players and coaches getting in and out of the stands for the annual group photo in less than seven minutes. Just as he did when he created the game plan, Harbaugh explained the assigned seating in a team meeting before everyone took the field.

“If you let the little things slide, the big things slide,” said offensive lineman Zion Johnson. “Details are everything.”

When some coaches make demanding demands or tell eccentric stories like the ones Harbaugh tells, the messages often fall on deaf ears, says Leaf. Not when Harbaugh is talking. The players laugh when asked about his rambling stories, but they still follow him to the last message.

“When you look at him and listen to him, you know he’s authentic,” Leaf said.

Due to a shoulder injury sustained by Leaf on the first day of training camp in 1999, Harbaugh took over as the starting lineup in his first year with the Chargers. The team finished 8-8 and the quarterback competition resumed in 2000. Harbaugh battled Leaf, who was then in his fourth season with the Chargers.

They were neck and neck during training camp. Leaf threw a game-winning touchdown pass in the final preseason game against the Arizona Cardinals, securing his starting spot. Harbaugh relented. Harbaugh accepted the position as a backup and shook Leaf’s hand.

“He then became this incredible mentor in the room,” Leaf said. “He taught me how to be a professional quarterback.”

Harbaugh began competing to be “the best backup quarterback in this league,” Leaf said.

It started with mentoring a quarterback whose career was marred by injuries and bad behavior. Leaf got into loud arguments with teammates, reporters and fans. When he misbehaved, everyone just added the latest infraction to the list of reasons to write him off.

Harbaugh instead asked why.

“I think people were admonishing me, the general manager, other teammates, the media,” Leaf said. “There was a sincerity behind the why, and then he listened. … That the coach had already instilled in him started to pay off.”

Receiver Derius Davis called Harbaugh a “player’s coach” who knows exactly what the players need because he himself had once stood in the same shoes.

Running back Hassan Haskins, who played at Michigan, knew he wanted to play for Harbaugh because the coach had created a family atmosphere around the program.

Offensive lineman Foster Sarell noted that Harbaugh often sits with the players at lunch and asks them about their families and spouses. He participates in Bible study with the players.

“He is a success machine,” said Sarell. “He is a cultural creator.”

Harbaugh has proven his ability at every level and at every stop, leading the University of San Diego to a 29-6 record in three seasons.

He orchestrated what Riley called “one of the best coaching jobs I’ve ever seen” by turning Stanford, which had a 1-11 record the season before his arrival, into the Pac-12’s dominant force.

He led the San Francisco 49ers to three NFC championship games in four years and then his alma mater Michigan to its first national championship in 26 years.

Riley, who had watched and cheered on the Chargers and Herbert from afar over the past few years, was thrilled to see his former player back in the sky blue uniform as coach. Harbaugh was the only veteran practicing with the rookies. He was the only starting quarterback Riley had ever seen involved in a fight.

Now he is the man whose job it is to breathe new life into the Chargers.