ESPN.com and ESPN The Magazine sought a list of the 20 current players who a 20-member Pro Football Hall of Fame panel and ESPN's John Clayton believe could excel in any era of the NFL.

Or, to put a finer point on it -- when Mike Ditka looks at today's player, whom does he want lining up next to him or across from him?

Which of today's players did our group of Hall of Famers deem really old school?

The playing days for our 20-member Hall of Fame panel spanned the '60s (Jim Brown) to the turn of the century (John Randle).

We presented four players a day, culminating with our top four Friday.

Use the #NFLAnyEra Twitter hashtag to get involved in the conversation or just follow along at @ESPN or on our Facebook page.

Honorable mention and No. 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8

7 | 6 | 5 | 4 | 3 | 2 | 1 | NFL Blog Network reaction

#NFLANYERA TOP 20

WHAT THE HALL OF FAMERS SAY ABOUT STEELERS S TROY POLAMALU

LYNN SWANN: Troy Polamalu is not afraid to take risks. I see him jumping over the offensive line and making a stop at the goal line. That takes timing, that's Troy going with his gut and knowing what he's studied and not being afraid to take risks. A lot of guys know tendencies but are too scared to take the risk or don't know what to do with it. Troy will jump over the line, he'll hit a guy behind the line of scrimmage, he'll force a fumble flying through the air.

FLOYD LITTLE: He gets hurt all the time, he gets concussions, his shoulder gets bent out of shape, but you can't keep him off the field. He's not that big, not that fast, but he's everywhere and everyone needs to know where he is when they line up.

JOHN RANDLE: If I was a receiver and I had to go against that guy, I'd definitely look out for him. He's another guy who plays like he's from that old Steelers era. In my second year, I remember guys telling me, "You have to know the difference between being injured and playing hurt. Sometimes you have to bear the pain and come out there because to be a legend in this game you have to play hurt." Polamalu exemplifies what that means. If I was a safety, I'd want to be like Polamalu and definitely want to have that hair, too.

LARRY CSONKA: Troy Polamalu sticks his nose in there and knocks himself cold to make a play. The man is fun to watch. He is from the old school. He over-learns the tendencies of the offense and sets the QBs up with a false-looking drop and then makes a beeline for the point he knows the ball is going to be thrown to. And if doesn't intercept it, he causes a disturbance.

WARREN MOON: Troy Polamalu is a throwback player. Tough, hard-nosed, does whatever is asked, throws his body around. He throws it around so much that he gets hurt and knocks himself out with concussions. But when he gets hurt, they have to hide his helmet to keep him off the field. He will give you everything he's got. He is one of the nicest guys off the field and he turns into the Tasmanian Devil on it.

MARCUS ALLEN: Troy Polamalu has a unique tenacity that is timeless, that crosses football generations. He could play in a leather helmet.

POLAMALU ON HIS TOUGHEST NFL MOMENT

Polamalu has dealt with seven head injuries since high school football, including two in a seven-game period this season. He never missed a game and finished third on the team with 91 tackles. Polamalu said there's always a struggle between the threat of serious injury and not letting it affect his performance.

That's the fear I think that any player faces. And that's the fear that any individual faces, overcoming any certain fears of being a coward, you know, and letting your teammates down or turning down a hit. That's the beautiful thing about sports is these fears are right in your face and it's pretty obvious if you turn them down or not.

Oh, I have the fear, no question about it. But I'm willing to fight it, for sure. I don't know if it's possible at this point to change style of play. I think that's the case for anybody in the NFL, especially regarding the rules and the fines that we have. They're going to continue to happen just because we're instinctual players at this point, you know? Of course we're professional athletes, but it's still tough to change these habits that we've formed since we were 8 years old.

ESPN.COM'S JOHN CLAYTON ON POLAMALU

He's changed the way people look at safeties. His ability to run full speed into spots before plays to confuse quarterbacks and his ability to close for tackles is as great as any player in football history. There's no one to compare him to in the history of football.

CLAYTON ON HALL OF FAME CHANCES: Safeties have a hard time making the Hall of Fame, but Polamalu would have the best chance of being enshrined.

John Clayton, a recipient of the Pro Football Hall of Fame's McCann Award for distinguished reporting, is a senior writer for ESPN.com. Follow Clayton on Twitter @ClaytonESPN

ON TWITTER #NFLNYERA

Very Cool. 4 Steelers on this list. #NFLAnyEra: No. 2 Steelers S Troy Polamalu - ESPN es.pn/A935ju — pwampler25 (@pwampler25) January 27, 2012

#NFLAnyEra has Troy 2, Ben 3, and James Harrison 10, and Hines 9 Shows why @steelers are one of the best=recipe for winning never changes — Andrew Pregler (@acpregler) January 27, 2012

#NFLANYERA TOP 20

Honorable mention and No. 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8

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Additional reporting by ESPN The Magazine's Morty Ain, Louise Cornetta, Amy Parlapiano and Alyssa Roenigk.