SANTA CLARA — There is no guarantee the 49ers will be back in this situation.
They made it to the NFC Championship Game in each of the previous two seasons. They came up short for a variety of reasons.
Once again, here they are.
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The 49ers face the Detroit Lions at 3:30 p.m. PT on Sunday at Levi's Stadium with a trip to Super Bowl LVIII on the line.
San Francisco must play a lot better in this game than it did last week against the Green Bay Packers, that’s for sure.
And here are the five players in this game that must step up for the 49ers:
5, CB Ambry Thomas
San Francisco 49ers
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The 49ers’ pass defense got a lot better after the bye week when the team turned to cornerback Ambry Thomas to enter the game in nickel situations.
But Thomas had a bad game against Green Bay, and figures to be the player on the 49ers’ defense that the Lions will target.
The Packers made big plays any time they went after Thomas, including two pass-interference penalties.
Thomas blamed his poor performance on the amount of time he missed, including Week 18 after he underwent surgery to repair a broken hand.
“I feel like I had to get back in the groove of things,” Thomas told NBC Sports Bay Area’s Jennifer Lee Chan. “Me being out that timespan not practicing, those reps are important during this time. This week I’m getting them back and getting back into the rhythm of things.”
If the 49ers do not deploy corner Charvarius Ward to shadow Lions wide receiver Amon-Ra St. Brown, then it seems like a good bet the Lions will try to take advantage of his matchup against Thomas in key situations.
4, WR Brandon Aiyuk
The weakness of the Lions’ defense is their cornerbacks. They’ve given up tons of yards to the opposition’s top receivers.
While all the talk this week has been about wide receiver Deebo Samuel’s health, the player who has the ability to put together a huge game is Brandon Aiyuk.
Whether he’s matched against cornerback Cameron Sutton on one side or Kindle Vildor across the way, Aiyuk has a chance to feast.
Aiyuk should have the advantage any time he’s lined up on the outside in one-on-one matchups. His route-running and yards after the catch could turn this game. The Lions’ defensive backfield is not particularly physical nor are the players sure-tacklers.
Big plays are there to be made, and Aiyuk could be the 49ers’ best option.
3, LB Dre Greenlaw
It’s not just a catchy nickname, it’s reality.
Big Play Dre.
Linebacker Dre Greenlaw’s goal-line stop against the Seattle Seahawks on the final week of the 2019 NFL regular season was the key moment in the 49ers’ last Super Bowl appearance.
And the 49ers would not have made it out of the NFC divisional playoff round without his game-turning plays against Green Bay.
The 49ers’ pass rush has to be better to cause a little chaos for quarterback Jared Goff and to get him off rhythm. And Goff will try to hit passes over the middle of the field.
And that’s where Greenlaw comes in.
Whether he’s defending tight end Sam LaPorta over the middle or tracking down Lions running backs Jahmyr Gibbs or David Montgomery, Greenlaw must produce a big day for the 49ers’ defense to do its part to win this game.
2, QB Brock Purdy
For 3 1/2 quarters last week, Brock Purdy just seemed off.
Was it the layoff? Was it the wet football and rainy conditions?
None of that matters now.
There should be good weather conditions and a fast track on Sunday. And the 49ers need Purdy to be the steady performer he’s mostly been since he took over the starting job nearly 14 months ago.
Purdy must be decisive and on-point against the Lions, who like to generate pressure with a variety of pressure packages.
He generally has been good about exposing the defense's weaknesses. He will have his opportunities on Sunday, and he must deliver.
Forget all that “system quarterback” and “game manager” stuff. The 49ers rely on Purdy to make plays, and he has to deliver in this game to make sure the team’s season does not end right now.
1, Levi’s Stadium
The offseason program, OTAs, training camp and regular season all led to this.
From the moment the 49ers’ season ended a year ago, their goal was to make sure they did not have to travel the next time they made it to this point in the season.
The Lions are a dome team. Not surprisingly, they fared a lot better in their home stadium than on the road.
Detroit is 11-3 on artificial turf this season. When they head out on the road, the results are different. They are 3-2 on grass playing surfaces.
Then, there’s the element of the home-crowd advantage.
All-Pro tight end George Kittle said he feels the difference that the home fans make during the flow of a game.
“Whenever we need a big play, I always say, ‘Come on, Levi’s Stadium, give me something good.’ And they always give me something good,” Kittle said.
“It’s such an awesome atmosphere, and you can feel the love from everyone out there.”