San Francisco 49ers defensive tackle Javon Hargrave requires surgery that likely will be season-ending after partially tearing his right triceps, coach Kyle Shanahan said Monday.

Hargrave sustained the injury during San Francisco’s 27-24 loss to the Los Angeles Rams on Sunday.

“It’s a big (loss),” Shanahan said. “I thought he had his best game (Sunday). I thought he was a huge factor, really affected the quarterback in that game. … He’s one of our better players. He was definitely going in the right direction and was going to have a big year.”

Shanahan said there is a chance that Hargrave does can back, but it wouldn’t be until late in the playoffs.

Hargrave, 31, had one sack and seven tackles in three games (all starts) for San Francisco this season.

Meanwhile, Niners quarterback Brock Purdy is dealing with an aching back. An MRI showed nothing serious, and Shanahan said that the 24-year-old is day-to-day.

In San Francisco’s first three games, Purdy completed 72.6 percent of his passes (69 of 95) for 842 yards and four touchdowns with one interception.

Christian McCaffrey has yet to play a snap for the 49ers this season, and Shanahan said Monday that the star running back went to Germany over the weekend to see a specialist as he continues to deal with nagging Achilles tendinitis.

McCaffrey has been on injured reserve since Sept. 14. Jordan Mason has taken over as RB1 during McCaffrey’s absence and has recorded 324 yards and two touchdowns on an NFL-high 67 carries through his first three games.

The Niners (1-2) will face the New England Patriots in Santa Clara, Calif., on Sunday.