The 49ers Expect Two Rookies to Pop in the Preseason

It's difficult to properly evaluate defensive players during practice.

They're not allowed to tackle. They're barely allowed to hit. So when they make a play, it's usually an interception or a pass breakup. Something involving coverage, which is inherently passive. Defenders chasing receivers or waiting for them to run into their zone.

Defensive coordinator Robert Saleh preaches extreme violence, something the players can't exhibit in practice. But they will during games. And the ones who are the most violent are the ones will play with the regular season starts.

Robert Saleh's vision for the defense

On Friday, Saleh discussed their development.

"I'll start with Nick," Saleh said. One thing we're not worried about with him is his violence, getting off a block, and understanding how to get to the football. He just has to continue mastering the scheme to give himself the opportunity to play fast.

"That part, from a rookie standpoint, he's got to catch up. But at the same time when he's in a position where he's comfortable to play call, he’s comfortable with what he sees pre-snap, you see everything that we drafted and that stuff is pretty good.

"Upton, he is a straining, scrappy young man, don't fall asleep on his size. I mean, the guy plays way bigger than he is and way bigger than he looks. He’s got a violence to him; he's got a violence to his demeanor. So, he's coming along really well too in that regard."

In practice, you can see that both Stout and Martin are eager to stick their noses in the action -- they simply can't unload they way they will next week when the 49ers face the Denver Broncos.

Stout is particularly interesting. As a nickelback, you'd think the 49ers would have drafted him because of his coverage. But it seems his coverage ability is secondary, and his hitting ability is the primary reason they took him. He was the strongest defensive back at the Combine, and he will improve the 49ers' run defense immediately even though he's just 5'8".

In coverage, his lack of height could hurt him in certain matchups when playing man-to-man. But the 49ers will live with those shortcomings if he throws his body around like he's a 220-pound safety.

I have a feeling that Stout and Martin will be quite to fun to watch in preseason. Stay tuned.