Seattle Seahawks running back Zach Charbonnet will miss the rest of the season because of a knee injury suffered in the team’s divisional-round playoff win over the San Francisco 49ers on Saturday night, coach Mike Macdonald said Monday on Seattle Sports radio.

“He’s got a significant knee injury, unfortunately,” Macdonald said. “Breaks your heart. He’s going to need surgery. He’s got a good, long road to come back.”

Charbonnet tore his ACL, a league source said.

The 25-year-old did not return to the game after being injured on an outside run in the second quarter. He spun off a tackle attempt by linebacker Dee Winters before being tackled by linebacker Eric Kendricks. Charbonnet was evaluated on the field and then in the medical tent before entering the locker room.

After the game, Macdonald said Charbonnet would need an MRI to determine the extent of the injury. He carried the ball five times for 20 yards and produced one first down before leaving.

A second-round pick in 2023, Charbonnet appeared in 16 of Seattle’s 17 regular-season games this year as Ken Walker III’s backup. He is the primary running back on obvious passing downs because of his pass-protection skills, and he often takes the bulk of the red-zone carries because of his physical running style. Charbonnet rushed for 730 yards and a team-best 12 touchdowns on 184 carries during the regular season, all career highs.

Walker shouldered more of the backfield load when Charbonnet went down and had his best game of the season against the 49ers, rushing for 116 yards and three touchdowns and tying his single-game career high. All three of Walker’s touchdowns came in the red zone; he had four such runs in the regular season.

Seattle’s other available running backs are Cam Akers and Velus Jones Jr. They’re both on the practice squad. Akers has not logged a carry as a Seahawk. Jones, who was active as the No. 3 running back Saturday, had four carries for 32 yards in Week 14.

Macdonald said quarterback Sam Darnold, who injured his oblique in practice Thursday and was questionable to face the 49ers, did not aggravate the injury in the game, though he said the issue will need to be managed through the remainder of the season. Left tackle Charles Cross, who left Saturday’s game in the third quarter and did not return “out of caution,” is day to day with a foot injury.

The Seahawks will host the Los Angeles Rams on Sunday in the NFC Championship Game.