Week 4's IDP headlines once again involved doing things. I feel like that's something I can write every week. For that reason we'll leave it at that and move forward. After all, there are quite a few interesting notes that have sprung forth as we reach the quarter mark of the season.One of the big surprises of the early part of the season has been the defense. A unit that was expected to follow up a historically bad 2013 season by being even worse in 2014 has instead turned Matisse Thybulle Jersey out to be quite tough to score on. Part of that turnaround can be owed to solid play by . The fourth-year linebacker has been quite active in the first four games of the season, notching a sack, scoring his first career touchdown and already setting a new career-high with four pa s deflections.It's certainly a welcome sight for a team that was left with plenty of questions at linebacker after went down with another season-ending injury. For fantasy owners, it's especially been an eye-opener. Carter has tallied 6-plus fantasy points in three of the first four games this season and is starting to take on a larger role in the context of the defense.However, not all is sunshine for Carter and the . Carter suffered a quad strain in the Week 4 win over the and is currently . There is concern that he might not be able to go this week against the . Keep an eye on the injury. Even if Carter isn't available to go in Week 5, he's worth a spot on your roster.Feeling FullerIt's been a rough start to the season for the secondary. That unit has been hit especially hard with injuries, most notably the season-ending injury to . While it hasn't done much for the group's productivity, it has allowed the spotlight to shine on rookie cornerback .Fuller burst on the scene with a pair of interceptions in the ' comeback win over the . He followed that up with another pick and a pair of forced fumbles the next week to help Chicago take down the . In all, Fuller is averaging nearly six fantasy points per game and is becoming a star in the defense.That's the good news. The bad news is that if Fuller continues to be playmaker in the secondary, teams might start going away from his side of the field. In the meantime, his recent play should merit a look from fantasy IDP enthusiasts and po sibly a spot on the roster.Four downs The secondary has been an i sue for the team all season long, but things could start to change with the news that is this week. Milliner struggled in coverage in his only game this season (Week 2 at Green Bay), but he's arguably the team's best corner and could be a playmaker this weekend against the in San Diego. safety is after a four-game suspension to begin the season. He'll slide back into a starting spot and should immediately become an IDP starting option after finishing 2013 in the top 10 among fantasy defensive backs. The beleaguered linebacking corps is getting some help this week with the of . A hamstring injury has kept Freeman out of action since the season opener and his lo s has been felt in the Indy defense. The third-year linebacker has posted 90-plus tackles in each of his first two seasons and is worth an add in most IDP leagues. One player who likely won't be back this weekend is rookie linebacker . Head coach says Shazier is still dealing with a knee injury and against the in Week 5. played the majority of the snaps in Shazier's stead, but for fantasy value you'd be better served to look elsewhere.Marcas Grant is a fantasy editor for NFL.com. Follow him on Twitter . Jahlil Okafor Jersey