Here's a look at three questions the Niners hope to answer in this one:
What happens at running back?
The battle for roster spots at running back didn't seem like it had much drama in store for this preseason, but business has picked up recently. Sure, Carlos Hyde is at the top of the depth chart and he's going to be there when the season starts. Behind him, though, the 49ers have a lot to figure out.
First and foremost, the Niners need to decide how many running backs they'll keep. Behind Hyde, they have Tim Hightower, Joe Williams, Matt Breida, Raheem Mostert and Kapri Bibbs. From that group, only Bibbs looks like he's a full-fledged long shot at this point. Breida looks like he's earned a job and could even be No. 2 on the depth chart when the season gets going. Williams has lagged behind a bit in terms of playing time, but given how highly the Niners thought of him in the draft, he's likely to stick as he develops.
The real battle here might be between Hightower and Mostert. Hightower is the experienced veteran who knows the offense and would provide some stability to the group. Mostert, meanwhile, offers more value on special teams and his strong performance against the Vikings in the third preseason game thrusts him squarely into the mix.
Coach Kyle Shanahan said Hightower will play Thursday night, something he didn't do against the Vikings. Hightower is still "in the mix" according to Shanahan, but he could use a productive night to help solidify his case.
"We’ve got some tough decisions here to make at running back, but we’re going to let it all play out," Shanahan said. "We definitely need this game on Thursday to see the other guys, too. They’ve all made it real tough on us.”
How does tight end shake out?
The Niners added some clarity to this position battle Tuesday when they traded Vance McDonald to the Pittsburgh Steelers, but there is still some jockeying for position that needs to take place. Rookie George Kittle is essentially a sure thing and could be a starter depending on matchups. Veteran Logan Paulsen is also in a good spot to land on the roster as the primary blocking tight end, though that's not as certain.
From there, the 49ers still have Garrett Celek, Blake Bell and Cole Hikutini in the mix. Fullback Kyle Juszczyk can also play tight end, which means the Niners probably don't need to keep more than three tight ends and could go with just two plus Juszczyk. If they do go with a third, there's much to consider among Celek, Bell and Hikutini.
Celek is the most established and is a good blocker. Bell has been around as well and is more of a "move" tight end, similar to Kittle. He's also been one of the Niners' most active special-teams players, participating on 54 special-teams snaps in the first three preseason games. Hikutini has some upside but hasn't done much on special teams and might be a better candidate for the practice squad.
All three figure to get a long look Thursday night and if one has a big night, it could tip the scales in helping the Niners make a decision before Saturday's cutdown deadline.
Who handles key special-teams roles?
Speaking of special teams, there's still a lot to figure out in mixing and matching on coverage units as well as on the return units. Special teams have struggled during the preseason, as the Niners have racked up penalties and given up some big returns. In fairness, many players who won't make the team have contributed to both of those issues.
Still, it's something Shanahan would like to get squared away and, more importantly, the Niners would like to identify some key special-teams contributors. Among those who are flying under the radar but bear watching are safeties Don Jones and Vinnie Sunseri, defensive back Adrian Colbert and Mostert, in addition to the tight ends mentioned above.
The 49ers are unlikely to make many big roster decisions based on what happens in this game, but special teams always offers a chance to make an impression and win a spot.