Mike Riley can laugh about it now – that time his starting quarterback fought his teammate.

As Riley, then the Chargers’ head coach, recalled, the team was on its way to its fourth straight loss. The Chargers failed to score a touchdown on the road against the Oakland Raiders. Chargers safety Michael Dumas, who called Riley “one of the toughest guys around,” said something to the team’s quarterback about the offensive woes.

Jim Harbaugh took offense. The quarterback pressed his facemask against Dumas’ and linebacker Junior Seau pulled them apart. It didn’t end up on the field.

“By the time they got to the locker room, they were fighting,” Riley said. “Jim didn’t back down.”

Nearly three decades after he was the maniacal quarterback who wasn’t afraid to take on his defensive teammate, Harbaugh brings the same passion to the franchise as its head coach.

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

Those who watched Harbaugh play know that his rare blend of competitiveness, authenticity and empathy make him the ideal person to pull off this feat. Sunday’s season opener against the Oakland Raiders kicks off at 1:05 p.m. at SoFi Stadium.

“He wants to win more than anybody, and he’s going to win,” former Chargers quarterback Ryan Leaf said. “He’s going to win. I just thought this was the best game in the world 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 proven veteran to mentor Leaf. Harbaugh, then in his 13th professional season, didn’t stop at coaching the former No. 2 overall pick.

During the offseason, Riley would occasionally look out his office window overlooking the practice fields as the rookies began their workouts. When he looked closer, he saw a veteran among the group.

“Jim was totally into his preparation for the season, for the game, whatever it was, he would always do whatever he could to be ready,” Riley said. “And in the games he was the ultimate competitor.”

Chargers quarterback Jim Harbaugh (4) hadn’t lost his competitive spirit when he arrived in San Diego.

(Stephen Dunn/Getty Images)

Even in a league filled with the most driven people in the world, Harbaugh is “the most competitive person you’ll ever meet,” Leaf said.

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

“He was like Michael Jordan,” Leaf said, referring to the basketball legend’s role in designing his private Florida court to better suit his playing style.

Harbaugh’s effort to find every advantage has extended to his famous attention to detail as a coach. Players are instructed to wear shoes — no flip-flops or slippers — to meetings when they have to get up and walk through a play. They put their shoes in a precise order in the weight room.

With his trademark “enthusiasm unknown to man,” Harbaugh organized a record-breaking team photo day, with players and coaches in and out of the stands for the annual group photo in less than seven minutes. Just as he does to set the game plan, Harbaugh explained seating assignments in a team meeting before everyone took the court.

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

When some coaches make such demanding requests or tell eccentric stories like the ones Harbaugh spins, the messages can fall on deaf ears, Leaf said. Not when Harbaugh is talking. Players laugh when asked about his meandering stories, but they follow him to the final message anyway.

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

A shoulder injury suffered by Leaf on the first day of training camp in 1999 led to Harbaugh becoming the starter during his first year with the Chargers. The team went 8-8 and the quarterback competition resumed in 2000 with Harbaugh facing off against Leaf, then in his fourth season with the Chargers.

They went pitch-for-pitch during training camp. Leaf threw a game-winning touchdown pass in the final preseason game against the Arizona Cardinals to secure the starting job. Harbaugh relented. Harbaugh accepted the backup position and shook Leaf’s hand.

“He became an 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 coaching the quarterback whose career was marked by injuries and bad behavior. Leaf got into shouting matches with teammates, reporters and fans. When he misbehaved, everyone added the latest infraction to the list of reasons to write him off.

Harbaugh instead asked why.

“I think people have admonished me, the general manager, other teammates, the media,” Leaf said. “There was a seriousness behind why, and he listened. … That coach was instilled in him when he started playing.”

Receiver Derius Davis called Harbaugh a “players’ coach” who knows exactly what players need because he was once in their shoes.

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

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

“He’s a winning machine,” Sarell said. “He’s a culture setter.”

Jim Harbaugh turned Stanford into a powerhouse when he became coach.

(David Madison/Getty Images)

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

He orchestrated what Riley described as “one of the best coaching assignments I’ve ever seen” in turning Stanford, which had gone 1-11 the season before his arrival, into the Pac-12’s dominant force.

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

Riley had been watching and cheering for the Chargers and Herbert from a distance for the past few years. He was thrilled to see his former player back in powder blue as a coach. Harbaugh was the only veteran who coached with the rookies. He was the only starting quarterback Riley ever saw get into a fight.

He is now the man who must breathe new life into the Chargers.