The San Francisco 49ers desperately need Brock Purdy to return from injury in Week 13 as their season hangs in the balance.

And it appears the quarterback is on track to do just that. 

Purdy sat out the 49ers' dismal 38-10 loss to the Green Bay Packers on Sunday with soreness in his throwing shoulder. It marked the first game he has missed through injury for the 49ers.

Sitting 5-6, the Niners' postseason hopes are dwindling, but Purdy could provide them with a boost going into a duel with a red-hot Buffalo Bills team in primetime.

Speaking in his Monday conference call with local media, head coach Kyle Shanahan revealed that Purdy had taken part in a light throwing session on Monday, and that he did so without issue.

Purdy will rest on Tuesday before being re-evaluated on Wednesday.

Said Shanahan: "He did some light throwing today and it went all good. He had, we didn't push it that hard, but did some light throwing, which was a good sign that the pain hadn't come back. And we'll rest it tomorrow and see how he feels as the week goes."

While Purdy looks to be taking positive steps towards a return, the statuses of All-Pro left tackle Trent Williams and star pass rusher Nick Bosa are still to be confirmed.

Williams (ankle) and Bosa (hips/obliques) also missed the blowout loss, but the Niners will hope to be able to remove them from a growing injury list in time for Sunday.

"They're in the same boat Brock is, really," Shanahan said. "We had the MRIs and everything, we kind of understand it, but just waiting to see how they respond. 

"They didn't respond great last week, that's why they weren't able to go. Nick and Trent are both in the same boat, Nick with his hip and oblique and Trent with his ankle. We'll evaluate as this week progresses and hopefully it turns a better corner than it did last week."

Added to that list on Monday was starting cornerback Deommodore Lenoir, who has undergone an MRI on a knee injury. Linebacker Demetrius Flannigan-Fowles is also dealing with a knee injury and is day-to-day.

Left guard Aaron Banks and defensive tackle Jordan Elliott are both in the concussion protocol while right guard Dominick Puni is dealing with a shoulder injury with the 49ers awaiting MRI results. Wide receiver Jacob Cowing remains in the concussion protocol.

A further blow to the interior offensive line came with the news that Jon Feliciano will not be activated from injured reserve. The versatile veteran's knee injury has not made the progress the 49ers hoped.

Rookie cornerback Renardo Green, meanwhile, is dealing with a neck issue and is day-to-day, but defensive tackle Kevin Givens is in the mix to finally make his return from a groin issue that has kept him out for the last four games.

Charvarius Ward, having missed the last three games following the tragic death of his daughter, will practice in full this week.

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