This one play defined Sam Shields' 2013 season and, really, his career.

He was beat. The goat. Wide receiver Miles Austin had a step on the Green Bay Packers cornerback with nothing but green acreage and a key NFC win ahead. Shields closed, picked off Tony Romo and the Packers completed the comeback.

So it begs a financial question: If Shields does surrender that touchdown, if the Packers do lose that game, does he get every penny of that four-year, $39 million deal that came three months later?

"I don't know about that," Shields says, smiling. "Luckily, it didn't happen. Because they would have got a first down and all that bad stuff would have happened. I made a play, something to help us win and that's what we needed."

He made the play and got paid. Now, the Packers are banking on more.

In a half-decade, Shields has evolved from ex-college wide receiver to undrafted postseason hero to the 2011 scapegoat of Green Bay's tackling woes to maturing into one of the league's top cover corners. The challenge is sustaining this all after cashing in — staying hungry.

After his best season as a pro — 61 tackles, 16 pass breakups and four interceptions in 14 games — containing Calvin Johnson, Brandon Marshall, Alshon Jeffery, Greg Jennings and rising Cordarrelle Patterson in the NFC North starts with Shields.

"I'll just keep playing how I've been playing," Shields said. "Everybody says that's something on me. I just let that go and keep playing how I've been playing."

Through the contract. And through what may be a new age in the NFL.

Ed Hochuli and his officiating crew littered Ray Nitschke Field with laundry on their Green Bay camp stop, making it clear that the league is cracking down even harder on illegal contact. That could mean trouble for pro cornerbacks, a position already fighting an uphill battle in this ratings-driven, player safety-driven, fantasy football-driven NFL.