By Steve Keating

DALLAS (Reuters) - On the gridiron Troy Polamalu is as wild and uncontrollable as his famous mop of tangled black hair.

Away from the field, the Pittsburgh Steelers safety is as quiet as an empty stadium.

A man of striking contrasts, Polamalu speaks softly and thoughtfully, a devoted father and husband but is one of the NFL's most feared and ferocious competitors with well-deserved nicknames such as "the Samoan Headhunter" and "Tasmanian Devil".

Yet for all his fame, Polamalu remains painfully humble and shy.

While all the signs point to a classic Jekyll and Hyde personality, Polamalu insists that what you see, is what you get; a hard-working, dedicated athlete, who just happens to go about his work with quiet, lethal effectiveness of a Stealth bomber.

"I try to represent something bigger than myself whether it is on the football field or off it, and to represent the same person," said Polamalu. "I wouldn't be someone who is a rah-rah 'look-at-me' guy on the field and not off the field and vice versa.

"I think if you see people like that, there's something that is not authentic in their life.

"They are either fake outside the football field or fake on the football field. I try to be the same person."

Polamalu has earned the admiration of his team mates and respect of opponents. Voted the NFL's defensive player of year, opposition quarterbacks ignore him at their peril.

Despite missing two games due to injury, Polamalu had seven interceptions and is a game changer when on the field.

"Troy is a great player, he's deserving of defensive player of the year," said Packers quarterback Aaron Rodgers. "Any time you play a guy like that you have to find where he is on the field.

"Baltimore didn't know where he was and he had a sack-fumble and ended up winning the game against them.

"He's a guy you have to account for."

Even Polamalu's team mates are in awe of his superman like ability to leap offensive lines with a single bound and bullet like speed that make it seem as if he is in two places at once.

He can hit like train and has the soft hand of wide receiver.

"I think what is even more amazing about him is his humility.

"He can do all these great things on the field and you'll never hear him talk about it.

"He is about team, it's great to be around a player like that with no ego."

(Editing by Julian Linden)