Brandon Marshall, OLB, DEN
Marshall was one of the league's elite IDP options early in the year while Danny Trevathan sat with a broken leg, but Trevathan's return two weeks ago threatened to move Marshall from LB1 status to LB3 territory. Indeed, after totaling 30 tackles in the first three weeks, Marshall posted just nine in the two games Trevathan played. Unfortunately for Trevathan, he suffered another serious leg fracture last week, this time in the knee area. That means Marshall should step back in as the lead linebacker for Denver, making him at least an LB2 for the time being.
Kemal Ishmael, S, ATL
Ishmael headed into this year behind all of William Moore, Dwight Lowery and Dezmen Southward on the presumed depth chart, and maybe even Zeke Motta, too. With Moore and Motta dealing with long-term injuries, however, an opportunity opened up for Ishmael, and he's been posting strong IDP production in the meantime. Ishmael has 33 tackles (21 solo) and an interception return for a touchdown in his last four games, and he should continue seeing plenty of tackle opportunities in a Falcons defense that can stop neither the run nor pass. Fellow starting safety Dwight Lowery has a cornerback background, furthermore, and doesn't really have the disposition of a high-volume tackler.
Jamie Collins and Dont'a Hightower, OLB, NE
Linebacker and top New England tackler Jerod Mayo will miss the rest of the season with a patellar tendon tear, which would leave Collins and Hightower as the two leading candidates to take up three-down roles at linebacker for the rest of the season. With Mayo out, Collins and Hightower both figure to see their tackle rate increase, too. Hightower (33 tackles in five games) and Collins (39 tackles in six games) should both approach LB2 value with Mayo (53 tackles) no longer beating them to ballcarriers.
Chad Greenway, OLB, MIN
Greenway is technically questionable for Sunday's game against Buffalo due to rib and hand injuries, but he practiced all week and generally is expected to return as Minnesota's top linebacker against the Bills. Playing next to a rookie (Anthony Barr) and a two-down player (Jasper Brinkley), at a glance it seems as if Greenway ought to be able to serve as the team's leading tackler once he returns to the field. As disappointing as the season has been so far to IDP owners who were hoping for LB1 production from Greenway, he just might give them that sort of production going forward.
Cortez Allen, CB, PIT
Allen has been a surprisingly useful IDP for a cornerback this year, totaling 37 tackles (32 solo) and two interceptions in six games, but he's earned a benching for poor play. Third corners very rarely hold fantasy value, so if you've relied on Allen up to this point, you might want to drop him for a potential replacement.
Bobby Wagner, MLB, SEA
Wagner is one of the absolute best defenders in the league, so it's disappointing that he'll miss time with a turf toe injury. Turf toe can be a problematic injury and usually pushes players into week-to-week territory, so Wagner's unfortunate owners shouldn't plan on him making an imminent return. With him out, the Seahawks will presumably rely on K.J. Wright and Malcolm Smith for more tackle production.
Wesley Woodyard, (3-4) ILB, TEN
Woodyard doesn't have any injury issues at the moment, but he seems to be losing snaps in the Tennessee defense anyway. Even with Zach Brown (pectoral) out for the year, Woodyard only played 64 percent of Tennessee's snaps against Jacksonville on Sunday. With 36 tackles in six games, Woodyard is loosely on track for 100 tackles this year, but he'll likely need to play at least 75 percent of the snaps going forward to pull it off.
Emmanuel Lemur, OLB, CIN
Lemur has been one of the more pleasant breakout IDP surprises of this year, totaling 37 tackles (22 solo) and an interception in five games, but he'll likely need to sit out this week's game against Indianapolis with a shoulder issue. With Lamur and Rey Maualuga both likely out, Vincent Rey might need to step into a three-down role next to Vontaze Burfict.
Eric Berry, S, KC
Berry will miss another game this week due to a high ankle sprain, and he evidently aggravated the injury during practice this week, which raises the concern of his absence potentially stretching beyond this week. With Berry out, the Chiefs will likely need to start Ron Parker.