GREEN BAY — As the preseason drew to a close, Kyler Fackrell felt something click.

The Packers’ outside linebacker fought the same battle all rookies face coming into the NFL – finding that right balance between thinking about your assignment and playing with reaction.

It took all summer for Fackrell to cultivate that confidence, but everything came into focus during the Packers’ preseason finale against Kansas City when the rookie third-round pick recorded 10 tackles (six for a loss) and a sack against the Chiefs.

The performance marked a turning point in Fackrell’s development and couldn’t have come at a better time with the regular season around the corner.

“I was finally really comfortable with (the assignments),” said Fackrell earlier this week. “So I didn’t have to be thinking about that anymore and let loose and play.”

Fackrell understood his role once the regular season began likely would be on special teams, with Clay Matthews, Nick Perry, Julius Peppers and Datone Jones leading the outside linebacker rotation.

However, the 6-foot-5, 245-pound rookie was summoned into action in Sunday’s 34-27 win over Detroit when Matthews (ankle/hamstring) and Jones (knee) were both inactive due to injury.

Fackrell ended up playing 37 defensive snaps against the Lions, rotating in with third-year linebacker Jayrone Elliott behind Perry and Peppers on the outside.

While the Packers didn’t have a sack of Lions QB Matthew Stafford through the first three quarters, linebackers coach Winston Moss told his rushers to stay upbeat and keep doing what they were doing.

“Our coach told us we just have to keep grinding, putting moves on them and keep working,” Fackrell said.

The pressure paid dividends in the fourth quarter when Perry sacked Stafford twice and Fackrell registered his first career sack for a 9-yard loss after beating Detroit left tackle Taylor Decker around the outside.

The three sacks over two series helped slow down the Lions and seal the win. Asked about Fackrell’s contribution after the game, Perry offered one word to describe the rookie linebacker’s performance.

“Huge,” said the fifth-year linebacker with satisfaction. “He learned from us – Pep, Clay, all of us – and all that stuff we feed him carries over to him making big plays. He’s as ready as any of us are.”

The rookie came close to fashioning a two-sack performance after beating Decker with a spin move. Fackrell lost his footing momentarily, which allowed Stafford to get the ball out.

Although Fackrell would’ve preferred Matthews and Jones were available to play, the rookie linebacker was excited after he was informed that he’d have a larger role in the defense. He had played only 14 defensive snaps in the first two games.

Based on his progress over the last month, the coaching staff didn’t have any qualms about rolling with Fackrell against the Lions.

“He’s done a nice job of improving every week,” defensive coordinator Dom Capers said. “He’s a young guy who applies himself. He’s gotten more opportunities each week. (Sunday), he had the most because of Clay and Datone being out. Jayrone was back fortunately. Kyler took advantage of his opportunities. He’s making progress.”

Fackrell’s role likely will decrease if Matthews and Jones are cleared to return after the bye week, but the rookie knows how important it is to get snaps with the defense early in the season.

The early bye means the Packers will have to navigate their final 13 regular-season games without a break. Fackrell hopes his early exposure will benefit him if he’s called upon again.

“I think it’ll be huge especially as we get later into the season,” he said. “It wears on your body, so (the coaches) being able to trust us to come in even if it is just a few plays here or there, I think will be huge.”