GREEN BAY – In the wake of Oren Burks' injury and uncertain status moving forward, the perspective on the Packers' competition at inside linebacker has changed.

Whereas the young quartet of second-year pro James Crawford, rookies Curtis Bolton and Ty Summers, and practice-squad holdover Brady Sheldon were thought to be battling to back up Blake Martinez and Burks, there's potentially a lot more on the line.

Burks left Thursday night's preseason opener against Houston early with what's being called a chest injury. Head Coach Matt LaFleur gave no update after Sunday's practice, only indicating more information is being gathered on Burks.

Whatever that means for the long haul, in the short term opportunity is knocking for several young linebackers looking to make a name for themselves with the second preseason game four days away.

"I'm not sure what's really going on with 'OB,' but for what it is right now, there's definitely an opportunity for all of us to step up and fill that role, for whoever it is that the coaches decide," Crawford said.

The last two days in practice, the one lining up next to Martinez with the No. 1 defense has been Bolton, an undrafted rookie from Oklahoma, whose journey is as unlikely as it gets.

A backup early in his college career, Bolton saw his redshirt junior season cut short by an ankle injury that led some to question whether he'd even come back for his fifth year. He did, earned a starting job and honorable mention All-Big 12 Conference recognition, but suffered through what he called "heartbreaking stuff" when he wasn't drafted despite fielding calls from several teams in the late rounds.

Having visited Green Bay in the pre-draft process, he liked the culture and opportunity and hasn't regretted for one moment coming to the Packers as a college free agent.

"All I know is this team took a chance on me and regardless if I was drafted third or fourth round or undrafted, I'm grateful to be here," Bolton said. "A guy like me was never supposed to be here."

Bolton likens himself to a "Swiss Army knife" as a linebacker who can both drop into coverage and provide some juice to the pass rush on a blitz. In the first preseason game, he was constantly on the attack but didn't wind up with as much to show for it as he should have.

"Yeah, I've got to finish plays," he said. "My first or second play in, I should have got a TFL, didn't get it. I tipped a pass and jumped, could've picked it, didn't pick it. I cleanly beat the running back on a pass rush, don't get the sack. Those are the things if you want to play in this league, you've got to finish those."

Summers was feeling similarly. Even though he led the defense against the Texans with 10 tackles (nine solo), he also missed a handful, perhaps partly due to fatigue from playing so many snaps in the first game.

Most important, according to position coach Kirk Olivadotti, is the converted quarterback and seventh-round pick from TCU showed the game "wasn't too big for him."

Summers has been working as the signal caller for the No. 2 defense, which has both forced him and helped him to learn a 3-4 scheme for the first time. As his brain has adjusted to new terminology (or old terminology with new meanings), he's grown more comfortable on the field as his unit's key communicator.

"It's going good," he said. "I'm finally feeling confident in giving checks and giving stunts and whatever it is. I'm a lot more confident, more vocal about it, so the guys around me believe I know what I'm talking about and I'm leading them in the right direction."

Summers made a great play in coverage in Saturday's practice, dropping into a middle zone and deflecting the ball to himself for an interception. Moments later, Sheldon got a pick of his own, making up for the interception he had knocked out of his arms in last Thursday's game as he tried to run with it the other way.

Sheldon and Crawford both came to the Packers last year as undrafted prospects. Sheldon, from Ferris State, originally was with the Raiders in both 2017 and 2018, went to the Browns, and then from Cleveland's practice squad to Green Bay's midway through last season.

Crawford, from Illinois, didn't arrive last year until two weeks into training camp but made such a strong impression on special teams he made the 53-man roster. Now viewed as a leader on the coverage units, Crawford has settled in on defense at inside linebacker after being tried both inside and outside a year ago.

Upon watching his game film from last Thursday, Crawford said he has to continue working to get off blocks, and that's his focus for the next preseason game in Baltimore.

"I definitely feel a lot better being in one position group," he said. "Last year I was kind of bouncing around and couldn't really focus and master one position."

Depending on the final prognosis with Burks, there could be one major position open on the Packers' defense at the start of 2019.

"Blake is the leader, and I think we have a pretty good group," Crawford said. "We've got a lot to learn from each other and keep growing together."