SANTA CLARA, Calif. -- When the San Francisco 49ers' defense prepared for mobile quarterbacks such as Seattle's Russell Wilson and Arizona's Kyler Murray in the past couple of years, they weren't exactly kept off balance in the practices leading up to the game.

Replicating the combination of arm talent with the speed and ability to escape that Wilson and Murray possess is not easy to do, which is why the Niners used a committee approach.

More often than not, backups C.J. Beathard or Nick Mullens handled the passing plays while wide receiver Richie James stepped in for designed quarterback runs and zone-read looks. The rotating quarterbacks were a significant hint to the defense of what was coming.

"The defense, who is trying to play honest, kind of gets an idea when you see [it]," Niners coach Kyle Shanahan said. "So, it's cool when they get the same guy every time and you never know what's going to happen."

Enter quarterback Trey Lance. To be sure, helping out the scout team offense didn't even sniff the list of reasons the 49ers traded three first-round picks to move from No. 12 to No. 3 in this year's NFL draft so they could select Lance. The Niners view Lance as their long-term answer at the game's most important position. He just hasn't ascended into that role yet.

Until that happens, the Niners' defense can benefit from Lance's presence as much or more than the offense on a day-to-day basis. At North Dakota State, Lance was a dual threat in the vein of Wilson or Murray, rushing for 1,325 yards and 18 touchdowns and throwing for 2,947 yards and 30 touchdowns while completing 65.4% of his passes in 19 games.

"With the option plays, zone-read-type plays as much as you can get a realistic look of it, the better it is," defensive coordinator DeMeco Ryans said. "I think for us getting a great look from Trey, very dynamic runner and thrower. He can do it all. For us to get a great look from him, it's the best thing we can ask for a defense. And we don't have to try to manufacture it by putting a wide receiver at quarterback or a running back back there and trying to do the old wildcat stuff. Like we get a real live look at a very bona fide quarterback who's capable of running all those plays."

That's no small thing for the Niners as they prepare to play Wilson on Sunday (4:05 p.m. ET, Fox) and Murray on Oct. 10. It's also important because the 49ers have been one of the worst at defending mobile quarterbacks over the past couple of seasons.

In 2020, the Niners allowed quarterbacks to rush for 446 yards, which ranked 31st in the NFL, and those signal-callers averaged 4.8 yards per carry (21st). In 2019, quarterbacks gouged San Francisco for 380 rushing yards (30th) and 5.21 yards per carry (27th).

While some of those issues are partly a product of having to see Wilson and Murray more frequently than most teams, it's not only that.

The Los Angeles Rams also have to see Wilson and Murray four times per season. In 2020, the Rams allowed opposing quarterbacks to rush for 242 yards (ninth) with an average of 4.25 yards per attempt (15th). In 2019, they yielded 216 rushing yards to quarterbacks (13th) and 3.6 yards per rush (eighth).

Three weeks into this season, the Niners have seen one mobile quarterback -- Philadelphia's Jalen Hurts -- and he gashed them for 82 yards on 10 carries while scoring the Eagles' lone touchdown. More often than not, the common thread in Hurts' success was a defensive lineman being too aggressive up the field or another defender losing track of his assignment as the play extended beyond the usual time, allowing Hurts an easy out to take off running.

"You have got to be able to line up and fit in your correct gaps," linebacker Fred Warner said. "Everybody has their own assignment and everybody has to be in the exact right spot. If one guy is out of his spot, that's where the hole is going to hit and the guy is out. That's just what that brings."

During a normal practice week, Lance takes about 80% of the scout team snaps, with practice squad signal-caller Nate Sudfeld getting the other 20%. That's about the standard for a backup quarterback, according to Shanahan. Every Friday, the Niners name practice squad "players of the week."

Before the win against the Eagles in Week 2, Lance was one of three honored. Defensive end Nick Bosa noticed the difference immediately.

"Scrambling, finding the hole and getting out on the edge and making throws downfield, it's pretty realistic work," Bosa said. "It's actually a really, really good look for us. It gives us a realistic look at if you get out of your rush lane what's going to happen."

Of course, Lance's scout-team work is also intended to help him continue to grow and develop as he awaits his opportunity with the starters. If all goes according to San Francisco's plan, Lance would give the defense fits in practice while continuing to show that he's on the right track to becoming the starting quarterback.

"It's also nice when you can do that and you have a quarterback like that, too, that the defense is playing against," Shanahan said. "If it's not there in rhythm, the same thing I'm going to want Trey to do in the game, run around, break the pocket, try to make a play. And that's where he can practice it and at the same time prepare our defense."