Caldwell coached Manning, a four-time NFL MVP, for a full decade. While Caldwell sees plenty in Flacco that makes him "dangerous," he's not trying to make the Ravens' starter the next Manning.
"Everybody's different," Caldwell told the team's official website. "(Flacco) has his own strengths, and what we want to try to do is accentuate those.
"I'm not here to try to make him like any other quarterback in this league, like Peyton Manning or Brad Johnson or the other guys I've coached. That's not my goal. He is who he is. What we want to do is just help him perfect what he does well."
Flacco, 27, has done plenty for his own resume, leading the Ravens to the playoffs in each of his first four seasons, and the team wants to extend his contract. Caldwell told the website he has seen growth in Flacco while preparing for him as an opponent, but the development of an NFL quarterback takes time and consistency.
"Joe's been able to show it for four years. He's continued to get better and lead his team to the playoffs. That's consistency," Caldwell said.
"Every once in a while, you will find a quarterback that will have one outstanding year and that's it. Every once in a while, you'll find one that has two pretty good years. And that's it for their entire career. The individuals that can string them back to back to back to back and continue, that's what you look for in terms of consistency and performing at a very high level."
Caldwell should know. He witnessed it for 10 seasons.