The Denver Broncos on Monday announced Joe Flacco would not be playing Sunday against the Browns.

In his place: quarterback Brandon Allen, who has been in the NFL for four seasons but hasn't taken a snap in a regular season game.

In the past, these scenarios would burn the Browns. An unknown quarterback would come to Cleveland or face the Browns at his home and shatter expectations en route to a stunning win. It would often serve as a demoralizing lesson that no games can be taken for granted in the NFL. 

These Browns don't need to learn that the hard way, though. 

"He has never taken an NFL snap, but he is in the league for a reason," defensive tackle Sheldon Richardson said of Allen. "Treat them all the same. Execute the game plan."

The game plan will be understandably intriguing because the Browns are equipped to make Allen's first start a long afternoon. But the level of aggression on the part of defensive coordinator Steve Wilks will be a factor to monitor because over-aggression could open the door for a quick hitter that turns into a long play or two for the Broncos. 

It's also a surprisingly difficult task because, well, there isn't much tape to study of Allen at the NFL level.

"I think you have to go back and really look at the preseason tape, which we have," Wilks said. "I coached against him in Jacksonville in 2017. I think he does some great things, Allen does. Very smart. You can tell he does a good job at protecting the ball. He does not hold onto the ball. He gets rid of the ball. Very athletic out in space. He can buy time with his feet and very accurate with the ball, as well. I still think their approach is going to be – because they have two dynamic running backs – they are going to try to run the football and create the play action off of it, which I think they do a great job of."

We should expect, then, an approach that mixes coverage with pressure. No team has a pair of edge rushers playing better in pass-rushing situations in the last three weeks than Myles Garrett and Olivier Vernon, according to Pro Football Focus metrics. When studying the Browns' defensive front on tape and attempting to apply it to an offense with a new starter, Broncos head coach Vic Fangio thinks similarly.

"They could be (more aggressive)," Fangio said of the Browns' defense. "There are always two schools of thought there. Sometimes if you are too aggressive, in some ways make it easy on the quarterback. He's got to get it out quick kind of and throw it, get an easier and quicker read possibly. Sometimes some people think play coverage and let's see if he can figure it out and by time for the rush to get there. I'm sure it will be a mix."

Realistically, the greater task for this Browns defense will be to stop Denver's rushing attack, as Wilks said. With Phillip Lindsay and Royce Freeman creating quite a young and effective one-two punch for the Broncos, the Browns should have their hands full. Then again, they handled a similar situation quite well last week against the Patriots, holding Sony Michel, Rex Burkhead and James White to a combined total of just 79 rushing yards.

They'll need to prepare more for an offense similar to that of the San Francisco 49ers, who gashed the Browns' defense for 275 rushing yards in Week 5. It was an all-around defeat for the team, with the lack of a defensive stand arguably the most glaring issue.  

They've since corrected it, and know offensive coordinator Rich Scangarello — who spent the last two seasons under Kyle Shanahan as the 49ers quarterbacks coach — will bring a similarly styled offense to the field Sunday. After admitting he tried to do too much, Wilks should be much better prepared to face such a run-first attack. 

And from there, it's about getting to Allen and causing mistakes. 

"We emphasize (forcing turnovers), we talk about it and we work on it in practice," Wilks said. "I think you have to put yourself in the situation in the game. I think that predicates sometimes based off your call and then also you just have to execute. That is the thing. We have to finish."