San Francisco 49ers star running back Christian McCaffrey has bilateral Achilles tendinitis, meaning he has it in both legs, per NBC Sports. McCaffrey recently went to Germany for treatment.

The 49ers said they expected to get a "better idea" on McCaffrey's status over the next few weeks. The team's plan was to ramp up his rehabilitation to "see how it responds." General manager John Lynch added that the team is aiming to "quiet down" the injury.

Related players: Jordan Mason, Isaac Guerendo, Patrick Taylor

The story said Achilles tendinitis is described as "an overuse injury of the Achilles tendon, the band of tissue that connects calf muscles at the back of the lower leg to your heel bone," according to the Mayo Clinic. Some Achilles tendinitis can be treated at home, while more serious cases can lead to tendon tears that may require surgery. The story went on to say, until McCaffrey, the team and the medical specialists see how the area responds to more work, it's hard to make a call on when he will be back, if he does come back this season. NFL Media reported Sunday that McCaffrey should be back, at least, by early November, but the report of bilateral Achilles tendinitis could change things. For now, Mason remains the bellcow. He had 24 carries in Week 4 with Deebo Samuel getting two. Guerendo had a fumble on special teams and had just one carry in the game.

And to top it off, 49ers RB Christian McCaffrey is seeing a specialist in Germany regarding his Achilles tendinitis.

Related players: Jordan Mason, Isaac Guerendo, Patrick Taylor

This doesn't sound good for CMC. Now owners can't help but wonder if McCaffrey will be back after missing his four games on IR. Mason has filled in well, gaining 5.2 yards per attempt with two touchdowns on the season. But at this point, with CMC seemingly a huge question mark, it may be time to pick up players like Guerendo and Taylor. Guerendo was the only other back to get carries in Week 3, running five times for 19 yards.

The 49ers are placing RB Christian McCaffrey (calf/Achilles) on injured reserve, per Adam Schefter of ESPN.

The 49ers had been leaning in this direction. They will now be without CMC for at least the next four weeks, meaning he will miss games against the Vikings, Rams, Patriots and Cardinals. He'll probably also miss a fifth game, as the 49ers have a short week after the Cardinals game before a Thursday night game in Week 6 against the Seahawks. Perhaps he can return for the Super Bowl LVIII rematch in Week 7 against the Chiefs. For now, it will be the Jordan Mason Show after his huge Week 1 performance against the Jets -- 28 carries, 147 yards.

The 49ers are now considering placing Christian McCaffrey on injured reserve, which would sideline him this week plus three more games, Shanahan said.

Related Players: Jordan Mason, Isaac Guerendo, Patrick Taylor

While it's possible that the team brings in another back, they sure weren't opposed to giving Jordan Mason a phenomenal workload last Monday. As it stands, Mason is a must-rostered, must-start option for as long as McCaffrey is out.

49ers RB Christian McCaffrey (Achilles/calf) feels like a long-shot for Sunday against the Vikings.

Related Players: Jordan Mason, Isaac Guerendo

Jordan Mason went nuclear as a last-minute start in Week 1, so he should be in fantasy lineups of McCaffrey misses again. Guerendo and even Patrick Taylor could be rotated in a little more in Week 2, but aren't worth fantasy stashes quite yet.

San Francisco 49ers head coach Kyle Shanahan pushed back at an earlier ESPN report that star running back Christian McCaffrey could miss Week 2.

When Shanahan was asked about the report from Adam Schefter after the 49ers' 32-19 win on Monday night over the Jets, Shanahan had a quip ready to go.

"That person must've been God," Shanahan said. He added that McCaffrey was a gametime decision on Monday night.

Related players: Jordan Mason

Schefter said McCaffrey pulled out of practice on Friday and no one was overly concerned at the time. But the calf was still tight on Monday before the game when he came in for treatment. However, it's not just his calf, he's also dealing with an Achilles issue. The team made the decision to play it safe since it's a long season and make CMC inactive, Schefter said. Schefter added it's a "strong possibility" McCaffrey won't play in Week 2, at Minnesota on turf. Mason had a huge game taking over for CMC on Monday night against the Jets. It's not necessarily a surprise as the team talked up Mason most of the summer. This is obviously worth monitoring and we can probably expect many different updates for the rest of the week leading up to Week 2. Mason should again be a nice play if CMC can't go. The Niners-Vikings game is also an early game on Sunday so owners will have time to adjust.

The 49ers will have wide receiver Brandon Aiyuk and left tackle Trent Williams against the Jets on Monday night, but they will not have running back Christian McCaffrey.

Jordan Mason, Patrick Taylor and Isaac Guerendo are the available backs for the Niners.

Definitely a shocker and likely a big blow to fantasy owners. According to the story, McCaffrey said on Friday that he had no doubt he would play and there was plenty of optimism from head coach Kyle Shanahan and General Manager John Lynch as well. McCaffrey missed most of the summer with a calf injury and is listed with an Achilles issue as well, the story said. Mason had a great camp and seemed to get a lot of attention from coaches this summer, and likely should get a bulk of the workload tonight against the Jets. Hopefully CMC owners backed themselves up during drafts by nabbing Mason. If Mason is still on your wire, he's worth picking up for any team in case CMC's issues are longer term. Taylor and Guerendo could get work for the Niners as well - if you're in a pinch losing CMC. From the Jets side, Braelon Allen and Israel Abanikanda could see touches behind Breece Hall.

49ers RB Christian McCaffrey is listed as questionable for Monday night's game against the Jets.

McCaffrey has been limited in practice. But when asked if there was any doubt about him playing Monday, he replied, "Nope." As long as McCaffrey is on the field, he is the No. 1 running back and maybe the No. 1 overall player in fantasy. Double-check his status Monday night but all signs point to him playing against the tough Jets defense.

Running back Christian McCaffrey has been sidelined with a calf injury since early in training camp, but Adam Schefter of ESPN reports that he is expected to take part in practice on Tuesday.

Related players: Jordan Mason

As the story said, the team won’t release an injury report detailing his level of participation until Thursday, but his return to the field is a good sign for his availability for the opener. The Niners were probably playing it very safe with who was most likely the number-one pick in your fantasy drafts. And, it's no surprise to see him back to work leading up to the first game of the season. CMC owners should still consider backing him up with Mason if at all possible.

Running back Elijah Mitchell went on season-ending injured reserve.

Related players: Christian McCaffrey, Jordan Mason, Isaac Guerendo, Matt Breida

Mitchell can only play this season if the 49ers reach an injury settlement with him and waive him from injured reserve, the story said. Mitchell has struggled to stay on the field but when he has played he's certainly impressed. Mason has had a good camp, according to reports and the team has praised his running style so he'll backup CMC. The team traded up to draft Guerendo, so there's a good chance he has a role this season as well.