49ers Kyle Shanahan shares when he first knew Texans DeMeco Ryans could be a head coach

Kyle Shanahan's San Francisco 49ers will face off against a familiar foe on Sunday when they face the Houston Texans. DeMeco Ryans, a former defensive coordinator for the 49ers, is now the head coach in Houston. And Shanahan's familiarity with Ryans goes back even farther than their time together in Santa Clara, to when Shanahan coached in Houston, and Ryans was a linebacker for the Texans.

At some point, Shanahan recognized something special in Ryans, which led him to tell the future Texans' coach that he could be a head coach in the NFL. Ryans, who is in his third season with Houston, recalled this week, "I remember sitting down in his office one day and he told me, 'Dude, you can be a head coach in this league.'"

Shanahan sat down with Matt Maiocco, of NBC Sports Bay Area, to discuss facing Ryans and the Texans. Maiocco asked Shanahan what he saw in Ryans that led him to believe the former linebacker had a future as an NFL head coach.

"It started with him as a player," Shanahan said. "He was different as a player. Anyone who can come in as a rookie and be a team captain, be the rookie of the year. I think he was the first guy in like 15 years or something to start at the Pro Bowl over Ray Lewis, something like that. I might be messing that up, but it was just unbelievable. They called him 'Mufasa,' like the lion in "The Lion King," because he was just so wise and stuff like that.

"And he was so young, but you could see that as a player. The four years I was with him, and then I had to go against him so much when he was at Philly and I was in Washington. So you just knew how he was out there and how he had such a natural feel for the game and how he carried himself. And then when he got into coaching, to see his work ethic, how he didn't say, 'I was this as a player, so I can skip some things. I don't have to do that.' He was extremely humble, wanted to learn it the right way, which is from the bottom up, and how fast he did it.

"He picked up things very fast as a coach, just like he did as a player. And when you have that kind of persona as a former player, when you carry yourself the way he does, when you are that good of a person, when you are that smart, when you do have that work ethic, I mean, to me, it's kind of a no-brainer."

The Texans, who currently sit at 2-4 this season, finished 10-7 in each of Ryans' first two seasons as their head coach. Both seasons ended with a loss in the Divisional Round of the AFC Playoffs after winning the AFC South. Despite the Texans struggling some this season, Shanahan knows Houston will be a tough matchup for the 49ers, especially facing Ryans' defense.

"They're [QB Mac Jones and the 49ers offense] going to be tested because this is a really good defense. Everyone talks about them. Their numbers are that, and it's what's advertised. DeMeco's got them playing at a very high level, very sound defense.

"But anytime you go against a defense who has extremely sound coverages, you want to know about their pass rush because sound coverages, it's tough to get big plays, but you usually can look people off and eventually get to a good hole. How does their pass rush allow you to do that? And they got the pass rush to go with it.

"So when you look at a quarterback in that situation, you gotta make sure he's able to get rid of the ball. You gotta make sure he's very conscientious of his depth and stuff, not just backpedaling and things like that. You gotta step up in there because the edges are too short, which does put a lot of pressure on your guards. And you gotta make sure that you take what the defense gives you when you can, get them to be a little aggressive when we got a chance for a bigger play. That's when we have to be aggressive also."

In his career as a head coach, Shanahan has had a lot of success against coaches he once coached with. This will be a big test for the 49ers, though. History says Shanahan has the advantage, but Ryans may be different from Shanahan's other past assistants. And he will try to prove that on Sunday.

Watch Maiocco's full interview with Shanahan below: