GREEN BAY – It still takes a few seconds for Morgan Burnett’s eyes to adjust each time he opens Instagram and sees Eddie Lacy in something other than Packers’ green and gold.

“It’s different seeing him in another uniform,” said the veteran safety with a smile after practice Wednesday.

Burnett squared off against Lacy on a daily basis in practice the past four years, but Sunday’s regular-season opener will be entirely new territory as the former Pro Bowl running back returns to Green Bay as a member of the Seattle Seahawks.

A second-round pick in 2013, Lacy rushed for 3,435 yards and 23 touchdowns in four seasons with the Packers before signing with Seattle as an unrestricted free agent in March.

The Seahawks, typically known for their run game, were in the market for a veteran back to join Thomas Rawls and C.J. Prosise after Seattle finished 25th in rushing offense in 2016.

After watching Lacy closely in the draft four years ago, the Seahawks felt the 27-year-old running back could be a fit. So far, they’ve been pleased with how Lacy has fit in.

“During the time he’s been with us, all of the work has been kind of an ascent,” Seattle coach Pete Carroll said. “He’s been building, recovering first, rehabbing. He did a great job. He was able to do a lot of work throughout the offseason with us. He really hasn’t missed anything. He’s been great about his conditioning work and all that stuff. He’s done a fantastic job, so he’s ready to play.”

After questions about his conditioning dominated his third NFL season, Lacy was off to the best start of his career last year – 71 carries for 360 yards (5.1 yards per carry) – before suffering a season-ending ankle injury against Dallas in Week 6.

It caused a domino effect in the Packers’ backfield, which also lost veteran backup James Starks for most of the season due to a knee injury and late-season concussion sustained in an automobile accident.

The job eventually trickled down to converted receiver Ty Montgomery, who seized the starting role and led the Packers with 457 rushing yards on 77 attempts.

A beloved member of the locker room, Lacy is still held in high regard among his former Packers teammates. Yet, it’s now up to Green Bay’s defense to stymie the former NFL offensive rookie of the year in his return to Lambeau Field.

Lacy, who rushed for 51 yards on 14 preseason carries, currently is listed as the No. 2 running back behind Rawls, but could be in line for extra work with Rawls still working his way back from an ankle injury that sidelined him for Seattle’s final three preseason games.

“I always felt Eddie was a great running back, one of the top in this league,” Burnett said. “It’s going to be different seeing him on the other side. Normally, you see him in practice. Now, in a live environment, it’s going to be different, but you have to be well-prepared because it’s going to take a group effort to tackle Eddie.”

Known for his pulverizing running style, Lacy presents a unique challenge to a Green Bay run defense that ranked eighth in the league a year ago. Still, the Packers are fully aware of what Lacy is capable of after seeing him carry the ball more than 500 times during his first two seasons.

Despite last year’s setback, Lacy is still considered as one of the NFL’s best backs when it comes to forcing missed tackles. He’s also still a nightmare for linebackers and defensive backs once he reaches the second level.

Green Bay constantly preaches the importance of “pursuit and finish” to its defenders. Whenever the 5-foot-11, 250-pound running back touches the ball Sunday, that mentality will be put to the test.

“Ah, Eddie, great player,” linebacker Nick Perry. “The biggest challenge against any big back is actually getting him down. You have to tackle. I think that’s a big component in going against those bigger guys is tackling right.

“They’re going to break some, but getting all hats to the ball is going to be the best way to bring big backs like that down.”

Quarterback Aaron Rodgers told reporters Wednesday he remembers Lacy for his “infectious smile” and toughness. While Lacy is still a friend to many in the Packers’ locker room, it’ll be all business once the teams hit the field on Sunday.

“Trust me, I know exactly how hard it is to tackle that guy,” safety Ha Ha Clinton-Dix said. “He’s a big back and definitely hard to bring down. If you think you’re going to hit him high and bring him down by yourself, then you have another thing coming. You have to take great angles, wrap up and get 11 guys to the ball."