Coach Kyle Shanahan said Tuesday that Williams (knee) is considered a "long shot" to play in Week 1 against the Rams, Dylan Grausz of NBC Sports reports.
Despite the relatively discouraging update, Shanahan did not completely rule out the possibility of Williams being back up to full speed by the start of the regular season. Like Williams, fellow edge rusher Nick Bosa is also recovering from an ACL tear suffered last year, and the 49ers have already seen multiple other injuries on the front seven, so there's a strong possibility they will have to call on some unlikely players to begin the new campaign.