With the Green Bay Packers cutting their roster down to 53 players two days after their final preseason game, Kenny Peterson's job was on the line. He struggled through much of training camp, and the Packers had several promising defensive linemen on the roster.

"He was on the wire," head coach Mike Sherman said. "And he knew it."

The third-year defensive lineman responded with an all-around performance against the Tennessee Titans to land a roster spot. And he has carried that momentum into the season. Through three games he has six tackles, amounting to one-fifth of his career total.

"He's been producing pretty good when he's been out there," Sherman said. "He's playing much better."

On Sunday he had one of his best games, stopping Tampa Bay Buccaneers running back Carnell Williams, the NFL's leading rusher, on back-to-back plays in the fourth quarter. After tackling Williams on a short pass for no gain, he and linebacker Nick Barnett held Williams to a one-yard gain on third down, forcing a punt.

"He made some big, big plays -- some we really needed," defensive tackle Corey Williams said.

Peterson has produced those kind of plays before. At The Ohio State University, he earned second-team All-Big Ten Conference honors during the Buckeyes' 2002 national championship season. During their Fiesta Bowl win against the University of Miami (Fla.), he recorded five tackles, three tackles for loss, two sacks and one forced fumble.

Despite that high profile college career, Peterson only produced 24 tackles and zero sacks during two regular seasons in the NFL.

He needed time to adapt to the pro game.

Although running backs, like Williams, can burst onto the NFL scene, it usually takes defensive lineman much longer. They face offensive lineman who know all of the tricks in the book.

"Defensive line is a lot harder because you're going against guys who have played a number of years," Peterson said. "There are so many technical things you have to learn and be aware of."

Peterson had to improve his hand placement. Honing that technique has allowed him to punch his hands inside a lineman's chest, lockout and disengage from blockers.

"If I didn't play with my hands," he said. "I'd let blockers get into me."

In addition to improving his fundamentals, Peterson has found a comfort zone on the interior. At 6-3, 285 pounds, he was a tweener -- bigger and slower than most defensive ends but faster and smaller than most defensive tackles. In college, he played defensive end for three years until his breakout senior season. During his first two years in the NFL, he played defensive tackle until the coaches tried him at defensive end during the recent training camp.

Peterson said he can play any position along the defensive line, but his performance impressed coaches once he moved back to tackle during the latter part of the preseason.

"He's a more effective inside player," Sherman said.

In that role, Peterson has played about 15 plays-a-game, but his repetitions could increase if he continues to improve his hand placement, recognition of offensive plays and speed.

"I've still got a lot of work to do," Peterson said. "My game is nowhere near complete."

But the 2003 third-round pick has made significant strides in 2005, starting with his final preseason game. His quarterback pressure in the third quarter forced Titans quarterback Billy Volek to throw an interception. In the fourth quarter, he stuffed running back Larry Croom for a three-yard loss.

Before that game Sherman called him into his office and told him that needed to step up his play. Remembering that uncertainty, Peterson plays every play like it could be his last.

"No matter what year you are, what position you are, you know you can lose your job at any moment," Peterson said.

These days, however, his job seems very secure.