Source: Niners hopeful LT Trent Williams to face Packers

Already without their starting quarterback, the 49ers are optimistic that star left tackle Trent Williams will be able to play Sunday at the Green Bay Packers,but San Francisco also needs to see how his injured ankle feels in pregame warmups to make sure he will be able to go, a source told ESPN's Adam Schefter.

If Williams is deemed fit to play, it would be welcome news for veteran quarterbackBrandon Allen, who will make his first start in more than two years in place of the injured Brock Purdy(shoulder).

Williams, who is officially listed as questionable, did not practice this week after playing through his injury in last Sunday's home loss to the Seattle Seahawks.

The Niners, who at 5-5 are fighting to stay in the postseason hunt, also have ruled out star pass rusherNick Bosa, who is dealing with injuries to both hips and obliques.