Christian McCaffrey will be out for the foreseeable future.

The San Francisco 49ers’ star running back missed the team’s first three games of the 2024 season due to Achilles tendonitis. Days before San Francisco’s Week 2 game against the Minnesota Vikings, McCaffrey was placed on injured reserve, keeping him out of action until at least Week 5.

Meanwhile, McCaffrey’s condition has only worsened.

The All-Pro traveled to Germany earlier this week to see a specialist for his condition. There, the specialist discovered what appeared to be a more serious injury to McCaffrey’s Achilles tendon.

Per Eric Branch of The San Francisco ChronicleThe Niners won’t be able to add McCaffrey back to the lineup any time soon. In an interview with Dr. Kenton Fibel, a Los Angeles-based sports medicine physician, told Branch that the tendon would take longer to heal than initially expected.

“I think it suggests more that it’s an injury that they think they’re going to need a little bit more to enhance his healing, which could take weeks or a few months rather than a week or two.” said Fibel (via The Chronicle). “Here it could be that you realize that the pathology is a little more serious and you reserve a way to allow him to return this season, even if it takes a month or two, because he needs a longer recovery.”

With McCaffrey out, San Francisco has turned to third-year player Jordan Mason, who has totaled 324 rushing yards on 67 attempts in three games. Mason has emerged as one of the Niners’ most important offensive players this season, scoring a rushing touchdown and at least 100 yards on the ground in each of the team’s first two games.

In addition to McCaffrey, San Francisco was without wide receiver Deebo Samuel (calf) and tight end George Kittle (hamstring), both of whom missed Week 3 against the Los Angeles Rams.

The Seattle Seahawks host the Niners in Week 6 for the first of two matchups between the division rivals in the 2024 season. The rematch in Santa Clara will take place in Week 11, meaning Seattle will not play McCaffrey at all this regular season.