he had a calf muscle strain from the pre-season but leading up to week one had calf and then Achilles ailles tendonitis is different than a calf muscle injury calf muscle injury can linger and get worse achilles tendonitis can linger but there is potential risk for Achilles tendon rupture this is why the 49ers will be very careful with CMC he's likely to miss week two maybe Beyond they have a good backup they're trying to be super bowl or bust here I see them being very careful with Christian mcaffrey because of even the slight chance of Achilles tendon rupture you got to be sure but he will return this season and be 100% the question is when but it isn't going to be week two or anytime in the very near future