The 49ers’ defense faces its stiffest challenge of the season on Sunday against the Baltimore Ravens’ top-ranked offense.

And it does not get any more difficult for the Ravens, either. The 49ers' defense is ranked No. 1 in the league, too.

“They have first-round picks coming off the bench,” Ravens offensive coordinator Greg Roman said Friday in his press conference with the Baltimore-area media. “They’ve really invested quite a bit in that area, and it shows on tape.

“The linebackers play very fast, run to the ball. And the secondary, led by Richard Sherman, is putting up some pretty good production. So, we have our work cut out for us. We’re very excited about it. Really, ever since we got off the plane from L.A., we’ve been really focused on one thing, and that’s getting ready for this game.”

The 49ers' defensive front is plastered with the first-round draft picks DeForest Buckner, Arik Armstead, Nick Bosa and Solomon Thomas. Dee Ford's availability for the game is in question due to a hamstring injury.

Bosa, the No. 2 overall pick, has certainly caught Roman's eye with eight sacks as a rookie. The addition of Bosa has brought another element to the 49ers’ defense this season, Roman said.

“Nick Bosa has made a huge impact, and when you watch the tape, he is extremely disruptive,” Roman said. “Their defensive line is taught in a style that is very aggressive, and he certainly fits that bill. He is an excellent player, run and pass, and he’s quite productive.

“The guy has a motor that goes and goes and goes. He’s a buzzsaw. You turn on the tape and watch a couple of plays, you pretty much have him figured out. He’s a handful.”

The Ravens will look to slow down the 49ers’ defensive line with their unique running game, which is trigged by quarterback Lamar Jackson, who leads the team with 876 yards rushing. He is adept at disguising his handoffs to running back Mark Ingram and Gus Edwards, both of whom average 5.2 yards a carry.

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“Really good ball-handling is what we’re interested in, and our guys have worked extremely hard at it,” Roman said. “I feel like when you look at where we were last year towards the end of the year, relative to this year, it is astronomically better.

”We don’t take anything for granted. But that’s something that we put, what I would call, an old-school emphasis on, and all the little details involved in it -- and there are many. The guys are doing a very good of embracing that.”