Haley's boss, Mike Tomlin, validated that belief last Sunday by going for it on fourth-and-10 from his own 10-yard line.
The players believe it now, too, after watching tape of the Steelers' first game this season against their next opponent, the Cincinnati Bengals.
"We've grown a lot," said wide receiver Jerricho Cotchery. "Looking at the film of the second game of the year against Cincinnati, it's a totally different offense. So, yeah, I think the growth has been there consistently with the offense. I definitely see it getting even better in the future."
Before we jump off into the future and deign the folly of this season as a potential step-up to greatness next season, let's look at some statistics.
Ben Roethlisberger specified the improvement this way: "Sacks have gone down. Turnovers have gone down. Points have gone up."
And so the dividing line, or the confluence of those three main sets of statistics, seems to have been the Detroit game.
Up until then, some of us wanted Haley fired; some of us wanted Roethlisberger traded. But now?
In the last four games, the Steelers have turned the ball over once, been sacked four times, and have averaged 28 points per game.
Within those four games, Roethlisberger has made his own professional history by going two consecutive games without being sacked and not having been intercepted in 189 passes, or since the first series of the Buffalo game.
In these last four games, Roethlisberger has a passer rating of 107.8, after posting a passer rating of 87.6 in the first nine games. The main reason for that statistical jump is the 11-0 touchdown-interception ratio.
Cotchery, the veteran of the receiving corps, explained the reason behind the reason.
"We've identified some areas where we've just been, well, great in," he said, and he pointed to the no-huddle approach, the spreading of the receivers, and Roethlisberger calling his own plays at the line.
"Obviously those plays he's calling are in Todd's offense," Cotchery said. "But he's just calling the plays and seeing what he wants. ... When you're able to see the defense and call what you want, you know where you're going to get someone. Those things naturally happen a lot faster."
Roethlisberger was said to have been very upset with himself for the early sack/fumble in the Miami game, and that it inspired him to remain focused on getting rid of the ball quickly.
If that focus continues, the Steelers' offense could be headed for heights it hasn't seen through even three Super Bowl appearances.
Roethlisberger was asked if the Steelers could next season become that runaway juggernaut type of offense that's been spotted in places like Green Bay, New Orleans and New England throughout his career.
"I hope so," he said. "We've seen improvements. We've gotten better every week. I think we've got a lot of pieces in place that can make that next step, and I think the cohesiveness that we have on offense is a good thing and hopefully can translate into these last couple games and then translate into the off-season."
The Steelers believe the blossoming of rookie running back Le'Veon Bell has been the most important new piece to the offensive puzzle this season. Next year they're hoping that "one of our big receivers can step up," according to a team source.
The Steelers' braintrust is also pleased with the development of third-round pick Markus Wheaton, whom they believe lost confidence and took a step back when his mangled pinky finger cost him five weeks of practice after London, but whom they believe was playing "right with the big boys" until then.
"We don't do a lot of four-receivers (sets). We do some, but we don't do a lot. Bruce Arians did a lot of four-receivers, five-receivers, but we don't do a lot of that here. So he's just waiting."
Is Wheaton a player on the rise? Will he become a key factor next season?
"He'll be ready to go, the way he works," Cotchery said. "He's a smaller guy but he studies, catches the ball well. He can run with the ball, too. He'll be ready to go."
Next season? Well, that's all they've got at this point. But it's possible that the learning process this season could turn out to be the necessary price to pay for a juggernaut, if one actually does emerge next season.
And judging from the last four games, that's a real possibility.
NOTES -- Jason Worilds had his first sack Sunday nullified by Elias, which called it instead "an aborted play." Worilds still leads the Steelers with seven sacks. ... DE Ziggy Hood (ankle), RT Marcus Gilbert (ankle), DE Brett Keisel (foot), NT Steve McLendon (ankle) and SS Troy Polamalu (shoulder) sat out of Wednesday's practice.