The San Francisco 49ers signed Christian McCaffrey to see what a supercharged sports car would look like in Kyle Shanahan’s offense, and the results were great.

But the hallmark of Shanahan’s offense, which dates back to Kyle’s father Mike and his time with the Denver Broncos, is bringing in running backs that nobody else wanted and having a ton of success with them. Running backs like Jordan Mason.

With McCaffrey unexpectedly unable to play Monday night due to a calf injury and Eli Mitchell on the injured list, this was Mason’s chance to step into a big role. And against one of the NFL’s best defenses, the undrafted free agent played the best game of his career in his first NFL appearance.

Mason rushed for 147 yards and a touchdown on 28 runs and led the 49ers to a surprisingly easy 32-19 victory over the New York Jets on Monday night.

Mason, of course, wasn’t the 49ers’ carry. Deebo Samuel Sr. took over backfield duties and scored a touchdown. George Kittle made the plays. Brock Purdy started slow but got hot once he settled in. Purdy threw to fullback Kyle Juszczyk for a 34-yard catch that set up a Mason touchdown early in the third quarter that effectively put the Jets out of the game. The 49ers’ defense is one of the best in the NFL and it showed. But Mason lived up to what every backup player dreams of, got his chance and shined when the spotlight was on him.

The 49ers offense was as good as ever, scoring eight straight points after a punt to start the game. San Francisco’s defense thwarted Aaron Rodgers’ return to the lineup after he missed most of last season with a torn Achilles tendon. Rodgers completed 13 of 21 passes for 167 yards, one touchdown and one interception.

The 49ers are clearly still better with McCaffrey. But the 49ers are the rare team that can put an undrafted free agent in the place of the reigning NFL Offensive Player of the Year and look just as good on offense.

49ers roll over the Jets

The night didn’t start off too badly for the Jets. Rodgers, playing in just his second game for New York and his first that lasted more than four snaps, led an impressive touchdown charge late in the first quarter. Breece Hall scored at the end and the Jets took a 7-3 lead.

New York’s defense looked good early on. The Jets pressured Purdy and stopped the run. After a Hall fumble in Jets territory, New York managed a quick three-and-out and the 49ers settled for a field goal. At this point, it seemed like the 49ers would have trouble moving the ball all night against a deep and formidable defense.

But the 49ers figured it out. They gave Purdy some time and he found the free receiver like he normally does. Although Brandon Aiyuk looked rusty after sitting out all of August looking for a new contract, Samuel, Kittle and Juwan Johnson made good moves.

Mason scored in the third quarter to give the 49ers a 23-7 lead, but then Rodgers made his first big mistake. He hesitated under pressure and then tried to place a pass to Garrett Wilson. But 49ers cornerback Deommodore Lenoir covered the ball excellently, deflected the pass and it was intercepted by linebacker Demetrius Flannigan-Fowles. The third quarter was only half over, but the game already seemed over. The 49ers defense would not have allowed that much.

The 49ers were not even three quarters into the season, but they already looked like one of the best teams in football. Even without McCaffrey, one of the best players in the NFL.

Jets still have work to do

Monday night’s performance must have been disheartening for the Jets. They had entered the season with renewed optimism after Rodgers returned, and it didn’t look like they were on the 49ers’ level. But it’s only the first week of the season. Rodgers, in particular, should get better once he works off some rust. After all, he had only played four regular season games since January 2023. New York should finish this season well.

The way the Jets went down probably said more about the 49ers. The Jets will end up with one of the best defenses in the NFL, but the 49ers were able to move them at the line, which opened up gaps for Mason, and there always seemed to be a receiver free when Purdy needed him. The 49ers defense is one of the best in the NFL and that’s a big reason why Rodgers’ first game back from injury was so quiet.

We’ll see how the Jets recover. We know what to expect from the 49ers by now. They’re a Super Bowl contender again. Just imagine how much better they’ll look with McCaffrey back in the fold.