SANTA CLARA -- Jordan Mason took the field at Levi's Stadium on Monday night with the weight of the world on his shoulders, but much like the onslaught of New York Jets defenders attempting to tackle the 49ers running back -- it didn't seem to phase him.
With reigning NFL Offensive Player of the Year Christian McCaffrey inactive due to a calf injury, Mason made an emphatic statement with the nation watching to the tune of a career-high 147 rushing yards on 28 carries in San Francisco's resounding 32-19 win over New York.
Following Monday's win, 49ers quarterback Brock Purdy praised Mason not only for his gaudy box-score statistics, but also for his ability to seamlessly step in for an invaluable player like McCaffrey and allow San Francisco's offense to not miss a beat in the process.
Stay in the game with the latest updates on your beloved Bay Area and California sports teams! Sign up here for our All Access Daily newsletter.
"Christian does a lot in the pass game. Dropping back and either going to him as a first option or knowing that he's my last option and there's a really good chance he's open," Purdy said. "But with JP, I think JP did a good job coming in and, there were some third downs and stuff where I was able to hit him on some check downs and him doing the same thing Christian has done.
"Obviously, Christian is the best in the league at running back and what he does. I'm not taking anything away from that. But I think JP did a good job of coming in and filling his void and doing his job to allow other guys to get open and allow us to run our offense."
Mason didn't just allow San Francisco to run its offense, he was the offense on a night where the 49ers pounded the Jets into submission with a relentless ground attack that racked up 180 rushing yards as a team.
San Francisco 49ers
Find the latest San Francisco 49ers news, highlights, analysis and more with NBC Sports Bay Area and California.
While Mason's coming out party might have stunned the national audience tuning in, the third-year running back's teammates were not surprised in the slightest to see him put together such an impressive outing.
"It's no surprise for me with the way he's been working in camp and how hard he runs," wide receiver Deebo Samuel said after Monday's win. "He's going to break tackles. That's just the standard of our team. He came out here and had a great day."
That next-man-up mentality is ingrained in what it means to be a 49er, something wide receiver Jauan Jennings echoed in the locker room on the heels of Mason's big night.
"JP, he played his tail off," Jennings said. "And it just shows how much we expect the next man up to come in and do the job as well as the first one."
It's a philosophy that is much easier said than done, particularly when the player you're replacing finished third in NFL MVP voting last season. One advantage that worked in Mason's favor was spending the majority of training camp as San Francisco's No. 1 back, where he earned the trust of his veteran teammates with the consistency he displayed on a daily basis.
"I'm not surprised, I'm not surprised," wide receiver Chris Conley said. "I've been seeing this work out of him for weeks at this point. Since the beginning of camp, I remember talking to ... I don't know if I said it to Brock, or if I said it to Deebo, but from the first day that he came out to practice, he looked different to me.
"Running the ball different, different focus, different determination. Happy for him, but I don't think anyone in this locker room is surprised."
Left guard Aaron Banks not only wasn't surprised, but he prophesized Mason's big night before kickoff on Monday.
"Personally, I kind of knew that if he gets the opportunity, he's going to take advantage of it. I had a feeling he was going for over 100 today," Banks said. "I think I told Jake [Brendel], 'Mason's going to go for 100 tonight.' I think he went like 140? Excited for him.
"Dude's strong, man. Strong, explosive, very downhill and you got to tackle him. You got to really tackle him."
The Jets' defense wasn't able to do that on Monday night, paving the way for Mason to become a household name overnight with a primetime performance that won't be forgotten any time soon.
It's unclear when McCaffrey will return to his role as the 49ers' No. 1 back, but Monday's statement performance solidifies one thing.
Mason shouldn't be viewed as a backup, but rather a complimentary piece that has the ability to take San Francisco's offense into the stratosphere as the franchise seeks a return to the Super Bowl this season.
Download and follow the 49ers Talk Podcast