Christian McCaffrey suffers major injury blow as concerning update emerges after 49ers star's Germany treatment trip

San Francisco 49ers running back Christian McCaffrey is suffering from bilateral Achilles tendinitis - meaning he is dealing with the medical issue in both of his legs.

McCaffrey recently hopped on a flight to Germany to undergo treatment for an injury that has kept him out since Week 2 of this NFL season.

Now, it's been revealed via multiple reports that the star Niners running back is dealing with the same issue in both of his legs.

Achilles tendinitis is described by the Mayo Clinic as 'an overuse injury of the Achilles tendon, the band of tissue that connects calf muscles at the back of the lower leg to the heel bone.'

According to the Mayo Clinic, most cases can be treated with at-home care - while more serious cases can lead to Achilles ruptures that might require surgery.

The team said they expected to get a 'better idea' on the running back's status in the course of the next few weeks - with the plan to ramp up his rehab to see how his body will respond. 

'And now, we're going to start hitting the rehab harder and trying to get him back into football stuff and see how it responds,' Niners head coach Kyle Shanahan said last week. 'So we'll see how he responds here. We've let him rest here for a couple of weeks.'

It's not clear when McCaffrey is expected to be back - with ESPN's Adam Schefter reporting that even the running back himself is unaware of when he'll return.

'I don't think Christian McCaffrey knows when he's coming back. I don't think the 49ers know when he's coming back. I don't think anyone knows right now when he's coming back,' Schefter said Monday on 'The Pat McAfee Show.' 

'They are going to begin to ramp up Christian McCaffrey, potentially even this week, starting to get him back to see how he's feeling. 

And ideally, you'd like to hope and think that he's feeling better -- that the time off will have helped -- but who knows how the calf and Achilles is going to react. Nobody can say for certain.'

While it's unclear when he'll be back, Schefter also reported that the idea of losing McCaffrey for the season 'never has occurred' for San Francisco. 

This is not the first time the San Francisco star has dealt with injuries to his lower body - suffering both a hamstring injury and an ankle injury in the 2021 season as a member of the Carolina Panthers.

McCaffrey was placed on injured reserve by the team ahead of Week 2 - which means, at minimum, he won't see the field again until at least Week 6 against the Seattle Seahawks.

This injury update comes after the Niners went through multiple injury scares to key position players.

Just two weeks ago, San Francisco was handed a loss with the team missing star tight end George Kittle and top wide receiver Deebo Samuel.

However, both players returned to action this past Sunday to help the team beat the New England Patriots.