The checklist for Allen on a given week never changes: Run to the ball. Don't get beat deep. Go where you're supposed to. When appropriate, hit somebody.
Allen has no delusions about what will happen whenever Polamalu's right calf finally heals. He'll go back to the bench and watch one of the best safeties of his generation go to work.
Until then — and Polamalu has already been ruled out for Monday night's home game against Kansas City — Allen will do his best to be Polamalu-lite.
"I'm just doing my job," Allen said Wednesday. "I just want to be on my Ps and Qs and I want to be effective and have urgency. When I'm reading my keys and I'm helping this team, that's the main thing that I care about."
The Steelers turned to Ryan Mundy to fill in when Polamalu initially hurt his calf in the season opener against Denver. Mundy, however, struggled in pass coverage and earned a couple of costly penalties at crucial times, most notably an unnecessary roughness penalty against Oakland that send wide receiver Darius Heyward-Bey to the hospital.
Polamalu returned against Philadelphia on Oct. 7, though his comeback lasted all of a quarter before he reinjured the calf, this time more seriously than the first. He hasn't stepped on the field since, though the secondary hasn't missed a beat.
Pittsburgh (5-3) leads the NFL in pass defense at the midway point, allowing 174 yards per game. That number is dropping every week and took a big plunge when Allen and company shut down Eli Manning and the defending Super Bowl-champion New York Giants last week in a season-turning 24-20 victory.
Manning completed 10 of 25 passes for 125 yards and an interception as the Steelers frustrated one of the league's most dynamic passing attacks.
Then again, it's becoming a habit.
Pittsburgh has beaten Andy Dalton, Robert Griffin III and Manning during its three-game winning streak, three very different quarterbacks with three very different ways of going about their business.
None of them were successful against a defense that has rediscovered its bite even without Polamalu and his flowing locks freelancing all over the field. The only place where the Steelers have really missed Polamalu is in splash plays.
There are few — if any — better than Polamalu when it comes to instinctively creating turnovers. With the four-time All-Pro standing on the sideline for the last month in grey sweats, Pittsburgh has taken the ball away just three times.
The Steelers hope those numbers will pick up against the woeful Chiefs (1-7), whose minus-21 turnover differential is by far the NFL's worst. Pittsburgh just doesn't need to get its hands on the ball to survive, though. The defense is just fine sending the opposition trudging off the field to punt, something happening with increasing regularity.
Pittsburgh is allowing teams to convert just 30 percent (11 of 37) of third down opportunities during its winning streak thanks to better execution on first and second down, and a sudden burst of chemistry in the secondary.
"We're starting to put the pieces together for where we need to be," cornerback Keenan Lewis said. "The (defensive) line, they're getting to the quarterback much faster. The linebackers are playing out of control. It's helping us out in the back end."
Then again, Lewis and fellow corner Ike Taylor are doing their part. Victimized early in the season — particularly in road losses to Oakland and Tennessee — the duo have shut down the likes of A.J. Green and Victor Cruz in recent weeks.
Lewis sent a message on the first play against New York, swatting down a deep ball from Manning to Hakeem Nicks. It was Lewis' way of saying he wasn't going to be intimidated by the surroundings or the circumstances.
"I just wanted to let 'em know that they can't catch us off guard," Lewis said.
The Giants never did. Taylor collected his first interception of the year late in the first quarter with a spectacular diving grab. It was a difficult catch, one that allowed him to laugh about the easy one that clanged off his chest in the end zone later in the game.
"I'm inconsistent," Taylor said. "You know my hands (are) suspect, that's just how it is."
Taylor knows he can afford to joke about it when the Steelers win but he's only too aware the drop extended a New York drive the Giants eventually scored on.
"Is it something we can work on? Yes," Taylor said. "Does it help your team out? Yes, because it gives the offense more opportunities to make plays."
Just don't expect the defense to take any unnecessary chances to make them happen. That's what Polamalu does. Until his familiar No. 43 is back in the lineup, Allen and the rest of his buddies are fine just sticking to the fundamentals.
Besides, in a way, Allen notes the only difference between a punt and a turnover is who gets to run around with the ball.
"The more and more we play together, the better we're getting," Allen said. "We've just got to continue executing and having a sense of urgency and attention to detail and playing fast and playing hard and I think that'll take us a long way."
NOTES: The Steelers signed WR Derek Moye and put him on the practice squad while cutting TE Jamie McCoy from the practice squad. ... Pittsburgh is 3-0 at home.