"Listen, I have so many things to worry about. I'm trying to go out there and play good football. I'm trying to go out there and play the best football of my life," Flacco told reporters Monday. "As far as a time constraint, and all that stuff, I'm not worried about developing guys or any of that. That is what it is. And like I said, I hope he does develop.
"But I don't look at that as my job. My job is to go win football games for this football team."
Broncos head coach Vic Fangio agreed with Flacco's assessment and said it's Lock's job to improve.
"Joe's a pro," Fangio told the team's official website. "Joe understands football, he gets it and he likes playing. That's on Drew to soak in and learn. Joe's learning a new system himself."
Flacco completed 232-of-379 pass attempts for 2,465 yards with 12 touchdowns and six interceptions in 2018.
The Broncos selected Lock with the 42nd overall pick in the 2019 NFL Draft in April.