In most cases, they will be rookies or younger players that have potential to make impacts either this year or within the next couple of seasons. Some may be already on rosters, but could potentially be had on the cheap.
Duke Riley (ATL): I would assume he's rostered in every dynasty format, but if you're able to pry him from his current owner, now's the time. Call me crazy but this could potentially be a Lavonte David / Kwon Alexander type of situation. Remember when David was a perennial top-3 fantasy linebacker? Then Alexander stepped in and started racking up all sorts of stats. Look, Deion Jones is a beast but Riley has already been plugged in as the WLB starter on Rotoworld. That may have been jumping the gun a bit, as the Falcons released their "official" starter package, and, for now Riley is backing up DeVondre Campbell. With Vic Beasley also manning a linebacker spot, Riley could easily see plenty of playing time from the outset, with Beasley better suited for an end/pass rush role. We've seen this defense plenty with what Seattle has done in the past, and Riley fits what they're looking for in this scheme. I've drafted or made attempts at rostering Riley in all my dynasty leagues. Could be a big mistake if he doesn't perform, but there's a good chance he is at least the 1b to Jones' 1a in the next year or two once they figure out how Campbell/Beasley are best used in this scheme.
Alex Anzalone (NOS): Probably another guy that is already rostered, but a guy I am really high on. If this guy can stay on the field and off the trainer's table, he has LB1 potential. The Saints released veteran/local guy Michael Mauti, clearing the way for Anzalone to get regular playing time, if not a starting spot from the outset. The problem(s) with Anzalone are: one, obviously, he's an injury waiting to happen. Two, Craig Robertson proved to be a more than servicable LB for the Saints. And three, the coaching staff really wants Stephone Anthony, who oozes talent, to stick and make an impact again. Not sold on Te'o as a consistently productive LB, so if Anzalone can hold off the aforementioned Robertson and Anthony, he could really produce solid numbers right from the start.
Kendell Beckwith (TBB): Here's a guy that may be on your wire, and one to watch. Most outlets report Beckwith as just a "2-down banger", but watching his tape reveals he can handle himself on passing downs. And this is a skill that is honed in the NFL. He's slated to be a backup at SLB, but I highly doubt a team on the rise like the Bucs would move up to grab a backup strong-side 'backer. Maybe they are grooming him to be Lavonte David's successor? Not sure, but I like the talent. If you have room on your taxi squad and want to take a flier, Beckwith could be the guy. See what he does in the first couple of weeks, and if either Alexander or David were to go down and he gets run backing them up instead of the SLB, then you better jump on it.
Kevin Minter (CIN): Remember when this guy was one of the top LBs taken in rookie drafts? Oh, and yeah I will eventually be listing non-LSU LBs! Anyways, really liking Minter right now, especially early in the season with Vontaze Burfict shelved. Now is Minter's time to shine, and he is currently running the middle for an aggressive Bengal defense, and won't come off the field. Rey Maualuga was set free and Vincent Rey is better as a part-timer, backing up Burfict. With Burfict's injury and "other" issues, Minter could easily be the top tackler for the Bengals this year. And he may come cheap.
Antonio Morrison (IND): Morrison will never be an elite LB1, but has a chance at securing a safe, LB2 tag. The Colts defense needs someone in the middle of the field to gobble up tackles, and after rotating the likes of Sean Spence and Edwin Jackson around, they appear to be settled on Morrison. Because of his "2-down thumper" status, he won't ever reach LB1 levels but could produce enough tackle-wise to be plugged in safely as a LB2/3. Look at what Edwin Jackson did last year.
Shaq Thompson (CAR): I can't believe this guy has only been in the league three years. Also, can't believe Thomas Davis is still hanging around. The Panther brass absolutely loves Davis, so figure he will retire as a Panther at the end of 2018. I expect Thompson to stay on through 2019 (club option) to see if he can be Davis' successor. No reason to think he can't do it. There's been talk of Thompson out-snapping Davis for at least a year now, and it just hasn't happened yet. So the Thompson owner could conceivably be tired of waiting around. Throw a 6th-round pick at him to see if he'll bite. In a year or two, Thompson could be putting up Davis-esque numbers.
Joe Schobert (CLE): We know the Browns will struggle offensively this year, and their defense, while a nice work in progress.... is still a work in progress. There will be oodles of tackles to be had and Schobert has earned himself the MLB job for the Browns. Jamie Collins is a stud and will gobble up tackles and big-play stats, and Christian Kirksey has been a reliable tackler, but this defense may indeed produce three startable LBs. A name to watch, especially if the Browns struggle like we think they will.
Derek Rivers (NEP): Rivers is out for the 2017 season, but if he's on the wire or you can acquire him cheap and stash him on your fantasy team's IR, we like his long term prospects. Trey Flowers is a bit undersized (height-wise) to be an effective edge guy for the Patriots defense. Rivers fits the mold better. Unless someone really shines in 2017 for the Patriots defense, expect Rivers to vie for a starting spot. He has Chandler Jones type upside in that defense.
Jerry Hughes (BUF): Rex Ryan effectively killed Hughes' value when he jumbled up an already-decent 4-3 defense into a mess of a 4-3 scheme. They had their moments, but Hughes was at his best as a defensive end in the 4-3. I will include him here, as an 8-year veteran, as I think he really outperforms his ADP and could maintain production for another 2-3 years.
DeMarcus Walker (DEN): Not sure why this guy isn't getting any love at the pro level, and in fantasy circles especially. The games I saw of him at FSU showed me that there are flashes of dominance here. The Denver defense produces solid edge rushing stats and if you're in a big play league Walker has some upside. Derek Wolfe and Jared Crick are decent, but strike me as "JAGs". Crick is only signed through this season and Wolfe is not cheap, so if Walker shows some talent, he could be a starter in 2018. One to watch for sure.
Eric Reid (SFO): Another guy who's definitely rostered, and as a 5-year veteran, wouldn't be a typical name you'd find on a list like this... but have to mention him here. I won't go so far as to say there's Landon Collins upside but the Niners have vowed that Reid will spend a lot of time closer to the line of scrimmage moving forward. Yes, they have two stud LBs in Navorro Bowman and Reuben Foster, but there will be tackles to be had in the box and he'll spend enough time in center field to get regular production. He should set career highs in solos and assists this season and could be a DB1 in 2017 and beyond. If you're light at DB and think you can get him cheap, he's a name we highly recommend.
Miles Killebrew (DET): Tavon Wilson is a free agent in 2018, and while his 2016 campaign was solid, Killebrew came in highly-touted and is a big hitter on the back end of the Lions defense. We expect Killebrew to get plenty of work in sub packages and if he ends up outperforming Wilson, Killebrew could supplant Wilson as the starter in 2018. Heck, if Wilson does perform well, but commands too much in free agency, the team could easily let him walk if they think Killebrew is a cheaper alternative.
Adoree Jackson (TEN): Sometimes you can just tell when a guy's "got it". Jackson has that "it" factor and the Titans recognized it early. He will play plenty on the defensive side of the ball, despite a shaky start to his preseason. He'll return punts and is a highlight waiting to happen. If your league separates CB/S, he's a guy you want for sure.