Texans Chick just posted a great piece about this subject.
And in her article, she posted a link to the following story during last year's playoffs:
Ed Reed unimpressed with Joe Flacco’s performance in playoffs
More importantly, Flacco left one of the Ravens' most important players with a distinctly unimpressed feeling. Talking to SIRIUS NFL Radio on Monday, mega-safety Ed Reed said that Flacco underperformed against Houston's aggressive defense.
"They had a lot of guys in the box on him and they were giving [the pass] to him," Reed said. "I think a couple of times he needed to get rid of the ball. It just didn't look like he had a hold on the offense. I don't know how much of [that was] the play calling … but it just didn't look like he had a hold on the offense, you know, of times past … It was just kind of like they [were] telling him [what] to do -- throw the ball or get it here, you know, get it to certain guys."
"He can't play like [he did against the Texans]," Reed continued. "One specific play that sticks out to me was when Ray Rice came out and got pushed out of the backfield and [Flacco] still threw him the ball and he had Torrey Smith on the outside. I can see that sitting on the sideline or sitting in the stands. You don't know what someone else is seeing."
Reed has always been a very vocal leader, both in good times and bad.