The Green Bay Packers have pinpointed their top backups at outside linebacker behind Clay Matthews and Nick Perry.

Defensive coordinator Mike Pettine recognized Reggie Gilbert and Kyler Fackrell as the two outside linebackers completing the quartet atop the depth chart at a position described by Pettine as “critical.”

“As far as the top four is concerned, we feel pretty good about that group,” Pettine said.

Gilbert has won the job as a top backup after finishing last season strong, attacking this offseason and producing at every turn this summer. He tallied 2.5 sacks and a forced fumble during a standout performance against the Pittsburgh Steelers last Thursday night.

“All you gotta do is watch the tape. Reggie’s done a good job,” Pettine said. “And he’s done a good job at practice too. It’s not just because he’s going against backups. He’s done a good job against our ones. He’s smart, he’s tough, he’s coachable. He’s done a real nice job for us.”

Pettine liked what he saw in Gilbert’s two-game stint after coming off the practice squad last season. The former undrafted free agent has carried over that momentum into 2018.

“I was impressed with the limited reps he got at the end of last year. He kind of jumped off the tape at that point,” Pettine said. “He’s just been ultra consistent in the spring. He doesn’t say much but he’s a great example of a guy used the resources. He comes in and works his tail off. He asks the right questions. He’s not a repeat offender, meaning he doesn’t make the same mistake multiple times. You’d love to have more guys like that.”

Gilbert will be joined by Fackrell, a third-year player who is still trying to find his way after two underwhelming seasons to start his NFL career. Pettine mentioned a snap against the Steelers in which Fackrell crashed inside, was knocked to the ground and lost the edge on a long run, but he’s otherwise liked what he’s seen.

“Fackrell’s had his ups and downs. There was the glaring mistake he made in the game, I’m not going to beat him up for that,” Pettine said. “Overall, he’s been consistent. He grades out well on the practice sheet.”

Pettine made no mention of second-year outside linebackers Vince Biegel or Chris Odom, the presumed third-stringers.

The Packers might be unproven depth-wise, but Pettine is comfortable with Matthews and Perry as the starters. Perry passed his physical and came off the PUP list on Sunday, and he’s confident he’ll be able to play Week 1.

“It’s nice getting Nick back,” Pettine said. “We’re hopeful he’ll be prepared to take a decent workload in the opener.”