LOS ANGELES — Coach Jim Harbaugh said Monday that Los Angeles Chargers running back Najee Harris has a season-ending Achilles tear.

Harris collapsed on a play-action play in the second quarter of the Chargers’ 23-20 win Sunday over the Denver Broncos.

“It’s unfortunate … he was really playing good,” Harbaugh said. “… Najee will be back, I have no doubt about it.”

Harris, who signed as a free agent with the Chargers in March, landed on the non-football injury/illness list ahead of training camp after a July 4 fireworks mishap that damaged an eye.

He missed all the Chargers’ training camp practices but was ready for the beginning of the season. The Chargers had been increasing Harris’ workload each week, and on Sunday he appeared on track for his most carries and most productive game this season. He exited the game with a team-leading six carries for 28 rushing yards.

Harris had never missed a game in his NFL career, and his durability is one reason he was attractive to the Chargers.

He rushed for 1,000 yards in each of his first four seasons with the Pittsburgh Steelers. His physical style of running is one Harbaugh covets, and having Harris to start the season was seen as crucial for this team’s ceiling in 2025.

“It’s always too tough to lose a brother like that,” quarterback Justin Herbert said after the Broncos game. “And I think you never want to see that from any of your own players or an opponent, and we’re wishing for the best.”

The Chargers will play the New York Giants in Week 4.