Throughout the 2025 NFL season, SB Nation’s Doug Farrar writes about the game’s Secret Superstars — those players whose performances might slip under the radar for whatever reasons. In this installment, we focus on San Francisco 49ers left tackle Austen Pleasants, who went from NFL afterthought to Trent Williams replacement in the blink of an eye — and did a great job in the process.

At this point, the San Francisco 49ers’ injury situation borders on the hilariously insane. Kyle Shanahan’s team hasn’t had Nick Bosa since Week 3, they haven’t had Fred Warner since Week 6, they haven’t had first-round pass-rusher Mykel Williams since Week 9, George Kittle was out for multiple weeks early in the season as was Brock Purdy, Brandon Aiyuk hasn’t been around all season for whatever reasons on Earth, and when Trent Williams went out of the 49ers’ Week 17 game against the Chicago Bears on Sunday night… well, a certain Jim Carrey meme came to mind.

Still, the 49ers had to shore it all up again, even with the future first-ballot Hall of Famer out with a hamstring issue, because they needed to keep pace with the Seattle Seahawks if Saturday’s Week 18 matchup would decide the NFC’s one-seed. This they did in a 42-38 win that was one of the most thrilling games of the 2025 season.

And who was it to replace Trent Williams? That would be Austen Pleasants, the 2020 undrafted free agent out of Ohio University who spent his first five NFL seasons bouncing on and off the practice squads of the (deep breath) Jacksonville Jaguars, Carolina Panthers, Los Angeles Chargers, Chicago Bears, Arizona Cardinals, the Chargers (again), the Cardinals (again), and the Bears (again).

It wasn’t until December 17, 2024, when the 49ers signed him to their practice squad, that Pleasants began to find any sense of order in his professional career. San Francisco re-signed Pleasants to a one-year, $960,000 contract in April of 2025, and before Sunday’s game, Pleasants had played a grand total of 12 offensive snaps in the 2025 season. This was primarily because Williams had been so durable until the seemingly inevitable happened.

And it wasn’t as if Pleasants looked like a Secret Superstar in 2024; he allowed four pressures in 67 overall snaps. Now, he was replacing the best left tackle of his era… in a must-win game… against a Bears defense without a truly dominant pass rusher, but a defense that can mess you up schematically with pressure if you’re not used to what you’re seeing.

At first, it looked as if it would be a big deal. With 9:41 left in the first half, Pleasants tried to get aggressive in his pass protection plan against Chicago edge-rusher Austin Booker, which allowed Booker to beat his man around the edge, and take Brock Purdy down with a show-off sack. Pleasants also allowed Booker to get around him for a hurry of Purdy with 11:33 left in the fourth quarter.

In 71 snaps (40 in pass pro), those were the only two quarterback disruptions Pleasants allowed.

So, okay. If Pleasants could negate edge-rushers around the arc at a dominant level, he wouldn’t have been having up update his Rolodex every other minute in his NFL journey. Beyond those two plays, he did more than enough to hold things up on his end, whether he had help to his side or not. The 6’7”, 330-pound Pleasants was a pleasant (sorry) surprise as a run-blocker, especially when it was time to seal the edge at the first and second levels. And as a pass protector, outside of the two gaffes we’ve already detailed, Pleasants did what a replacement-level offensive lineman should do — he made sure that nobody noticed him as much as humanly possible.

Purdy seems to love Pleasants both on and off the field, and he was more than happy to speak up for his buddy after the game.

“Yeah, he did amazing,” Purdy said. “Obviously to have Trent go down the first play it’s like, ‘Dang.’ Then Austen jumped right in. He’s a guy that we all love, and over the year he’s just been great in our locker room, and just one of the boys on the bus — like, everyone loves him. He’s done a great job just being ready all year. So, for him to go in and play well, like he did, and allow our offense to keep rolling and not lose a step, it was huge.

“We’ve all got his back, and he’s going to keep getting better too.”

Shanahan was more circumspect in his praise, but again, it’s all about barely being noticed when you’re that backup blocker.

“I mean, to play that whole game and to not be an issue, I think I only talked about him on one third down. So, my sense is he played really well.”

It remains to be seen how (or if) Williams will fare against the Seahawks’ brutal defense to end the regular season, and it’s obvious that the 49ers would be better off if Williams can go as close to 100% as anybody is at this point. But the alternative is now less than fatal if the bottom falls out at yet another starting position.

It’s a dance the 49ers have been dancing all season long, and Austen Pleasants is simply the next “Next Man Up.”