Five Bears on the roster bubble

Over the next eight days, the bubbles will burst for many fringe NFL roster candidates while a select few somehow manage to convince their coaches and general managers that they're too valuable to cut.

Indeed, the preseason matters - a lot - for thousands of players across the league. And it is wholly important for the following five Chicago Bears players who find themselves squarely on the bubble with only eight days and two preseason games remaining to try and cement roles on Matt Nagy's squad.

1. Linebacker Aaron Lynch

Timing is everything, right? Lynch had been sidelined since July 20 with a hamstring injury prior to getting his most extensive practice work of the summer in Thursday, less than one week after Leonard Floyd broke his hand in Denver.

Lynch is the Bears' second-most accomplished edge rusher, but beyond that fact, he has seemingly done nothing since his March arrival to prove that he belongs on the team. He was sidelined much of the offseason because of a hamstring issue and has a reputation of underachieving.

GM Ryan Pace guaranteed Lynch, the only rusher in Chicago's stable with anywhere near the length and pedigree of Floyd, $1.25 million in March based on his belief that the former 49er could reinvent himself by reuniting with Vic Fangio. Still, Nagy repeatedly has said that jobs must be earned.

2. Center Hroniss Grasu

It appeared in January like the hiring of Mark Helfrich might buy the Bears' third-rounder in 2015 a bit more time, as Grasu was a four-year starter with the Ducks under Chicago's new offensive coordinator. That time, however, might already have expired with Grasu yet to play in the preseason and James Daniels now occupying his second-team pivot post.

Grasu is one of the nicer guys and harder workers in the locker room, but he's already proven he can't play guard, and now it's increasingly appearing as if he can't stay healthy long enough to compete with a pair of better talents in Daniels and Cody Whitehair.

3. Defensive back Deiondre' Hall

The 127th overall pick in their 2016 class that included three safeties, Hall has endured plenty of growing pains - on and off the field. He was arrested last spring, months after a rookie campaign limited to eight games with an ankle injury, on charges of public intoxication and disorderly conduct. He spent his second in the doghouse, freed for only one defensive snap in two appearances, and was just suspended the first game of 2018 for a substance-abuse violation.

Hall was a fascinating prospect coming out of Northern Iowa, where the long-limbed (nearly 35-inch arms!) playmaker played almost every position in the secondary. Likely with that in mind, the Bears transitioned him last year to safety, where he remains behind Deon Bush and DeAndre Houston-Carson, both more established on defense and special teams. It's possible the broken arm DHC suffered in Denver opens the door one more time for Hall.

4. Wide receiver Javon Wims

If only late-round rookies Wims and Kylie Fitts were able to bottle up their NFL preseason debuts and continue tapping into them over the past couple of weeks ...

Wims was impressive against the Ravens in the Hall of Fame game, where he tallied game highs in targets (10), catches (seven) and receiving yards (89) while showing strong hands and a bit of post-catch playmaking. But he's been held to a combined four catches and 24 yards over the past two weeks, when he's played five fewer combined snaps on offense than he did in the opener.

Are the Bears trying to hide him in order to sneak Wims onto the practice squad? It feels that way. If Kevin White is locked in despite not playing in the third phase, Wims is probably battling with Josh Bellamy, Bennie Fowler and perhaps Tanner Gentry and Marlon Brown for one or maybe two spots.

5. Cornerback Marcus Cooper

Pace cut Cooper this winter just one season into a three-year, $16 million deal so he could bring him back on a more reasonable one-year, $1.5 million offer, including half of that guaranteed. Still, Cooper has carried over last year's struggles, getting roasted by the Bengals first-team offense and sitting out Saturday in Denver.

Although younger secondary players such as Kevin Toliver and Doran Grant haven't fared all that much better, they have more upside than Cooper, who probably is what he is at age 28 - impressive off the hoof but leaving you wanting more on the field.

• Arthur Arkush is the managing editor for Pro Football Weekly. For more on the NFL, visit profootballweekly.com and follow Arthur on Twitter @arthurarkush or @PFWeekly.