Source: Banged-up 49ers hopeful Williams plays

Already without their starting quarterback, the San Francisco 49ers are optimistic that star left tackle Trent Williams will be able to play Sunday against the Green Bay Packers but also need 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 quarterback Brandon Allen, who will make his first start in more than two years Sunday in place of the injured Brock Purdy.

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

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