The 49ers could be without their three most important players.

If the Green Bay Packers had to name three San Francisco 49ers players they were least looking forward to playing, they would probably say Brock Purdy, Trent Williams, and Nick Bosa.

All three could miss Sunday’s game at Lambeau Field.

Bosa’s status has been in doubt all week. He was already playing with a hip injury but suffered an oblique injury in the 49ers’ loss to the Seattle Seahawks last week. The All-Pro pass-rusher hasn’t practiced all week.

Now, there is added uncertainty about Purdy and Williams. Purdy is dealing with an injury to his throwing shoulder, while Williams hasn’t practiced due to an ankle injury.

According to Sports Illustrated’s Grant Cohn, Purdy attempted to throw for about five minutes of Thursday’s practice but couldn’t continue.

“My best interpretation is that they thought he might be able to throw today, he gave it a shot, and it didn’t work out,” said Cohn. “If I had to guess right now, I’m thinking Brandon Allen is going to start this game against the Packers.”

According to Eric Branch of the San Francisco Chronicle, Niners head coach Kyle Shanahan said Bosa and Williams are in jeopardy of not playing this week.

Wow.

Purdy, Williams, and Bosa are the 49ers’ best players.

While Purdy isn’t playing at the same level we saw last season, he is still highly efficient, throwing for 2,613 yards and 13 touchdowns with eight interceptions. He has the ability to make game-winning plays, as the Packers experienced in their playoff loss to the 49ers last January.

Williams is an 11-time Pro Bowler and is still playing at a high level this season. He is PFF’s eighth-ranked tackle for pass-blocking and run-blocking and has allowed only one sack.

Bosa is the 49ers’ pass-rush. It’s that simple. He leads the way with 52 pressures and eight sacks, making life far easier for those around him. According to ESPN Stats & Info (via Rob Demovsky), the Niners’ pressure rate drops from 33 percent to 18 percent without Bosa, while their sack percentage reduces from eight percent to two percent. Both would rank last in the NFL.

Losing any of these three players would have a significant impact on the game. The Niners could lose all three, or at the very least, they will play through injury.

The Packers have their own injury concerns ahead of a huge showdown at Lambeau Field, but the status of Purdy, Williams, and Bosa could dramatically impact who wins. It’s something to watch between now and Sunday.