For some, this is the week the fantasy regular season ends. For others, this is the first round of the playoffs. Either way, if you are reading this, you are looking for some help in a pivotal IDP matchup.

Welcome to our weekly column to help you win on the defensive side of the ball. Today we are here to review some IDP waiver wire pickups for Week 13. Week 12 saw mixed results, with some hits (Dannell Ellerbe, Lawrence Timmons, Daryl Worley, Tavon Wilson) and some whiffs (Derrick Morgan, Dont’a Hightower, Stephon Tuitt).

The following players are not necessarily “must start” players for IDP leagues, but rather, players that currently have below 25% ownership levels (in Yahoo! Leagues) and are suggested deep-league IDP additions for this week.

Editor's Note: Once you're done here, be sure to read about even more Week 13 waiver wire recommendations, for all fantasy-relevant positions. Just click on any link: ALL - RB - WR - TE - QB - DEF - FAAB - CUTS

Linebackers - Week 13 IDP Waiver Adds

Pernell McPhee, Bears

Matchup: vs. 49ers

Ownership: 0%

This is purely an example of opportunity and surviving the war of attrition that is the long NFL season. The Bears group of linebackers has become paper thin over the past two weeks, losing their talented starting inside linebacker duo to suspension (Jerrell Freeman) and a devastating injury (Danny Trevathan). McPhee, who missed a ton of time this season himself, remains the most accomplished linebacker on the Bears roster as of this point. Opportunity will be there for McPhee to be on the field for plenty of snaps and thus, produce tackles, sacks and other useful IDP statistics.

Denzel Perryman, Chargers

Matchup: vs. Buccaneers

Ownership: 2%

Those who have been following this weekly column know that I am a sucker for Perryman and his abilities. While he has undoubtedly been a disappointment this season from an IDP standpoint in what was supposed to be a year in which he took a giant leap forward, he spent much of the first 10 weeks in a deep rotation and banged up with injuries. Finally healthy and the most talented player remaining in the Bolts linebacker corps, Perryman returned last week and recorded 10 total tackles (six solo).

Justin Houston, Chiefs

Matchup: @ Falcons

Ownership: 8%

The Pro Bowl linebacker returned to action in Week 11, where he was eased back into the lineup and played a minimal role in the game. Week 12 was a different story for the Chiefs pass rushing ‘backer, and he looked as though he returned to his All-Pro form, finishing with 10 solo tackles and 3.0 sacks in Sunday night’s victory against the Broncos. Houston could be a major factor down the stretch for IDP owners savvy enough to pick him up, and will see plenty of chances against the pass-happy Falcons to sack Matt Ryan .

Eric Kendricks, Vikings

Matchup: vs. Cowboys (Thursday)

Ownership: 23%

Thursday Night Football finally delivers an intriguing matchup this week, despite the Vikings struggles. Much like Perryman, Kendricks was expected to take a massive statistical leap in his second year, but has been hampered by injuries and other issues. The matchup can’t get any better on Thursday night as Kendricks will be expected to anchor the center of the Vikings tough front seven as they look to slow the NFL’s best ground game led by Ezekiel Elliott.

Defensive Linemen - Week 13 IDP Waiver Adds

Marcell Dareus, Bills

Matchup: @ Raiders

Ownership: 3%

Dareus has not seen the field much in 2016, primarily due to a myriad of injuries and a brief suspension early in the campaign. When the Bills have had their anchor in the middle this season however, he has been a dominating figure, wreaking havoc in the backfield against opposing quarterbacks (3.5 sacks in three games) while also racking up tackles (16 total, including several for a loss). Though Dareus was seen on the sideline for the Bills defense final drive in their victory on Sunday, he is expected to be fine and ready to give the Oakland offensive line all they can handle.

Michael Bennett, Seahawks

Matchup: vs. Panthers

Ownership: 5%

The Seahawks will supposedly be getting back their most important defensive lineman this week, a guy Tom Brady recently said is one of the best defensive players in the entire league. Bennett will provide an injection of talent and energy into the Seahawks front that should be fired up to face Cam Newton.

Leonard Williams, Jets

Matchup: vs. Colts (Monday)

Ownership: 19%

Do not let the stat sheet fool you. Despite only registering two solo tackles in the Jets Week 12 loss to the Patriots, Williams was a problem for New England’s offensive line all day as he constantly hurried and hit Tom Brady. Unlike other highly touted Jets defensive lineman, Williams has played with heart and toughness all season and gets a dream matchup on Monday Night Football against the Colts porous line.

Defensive Backs - Week 13 IDP Waiver Adds

Daryl Worley, Panthers

Matchup: @ Seahawks

Ownership: 4%

I’m going back to the well here to ride the hot (and under-owned) hand in Worley. The rookie corner has been playing well over the last four weeks, and has become a valuable contributor to IDP leagues. Last week, I felt that Worley had a great matchup that would put him in position to make plays, and that’s exactly what he did, finishing with 12 tackles (one for loss) and two pass deflections. Look for Worley to see plenty of action once again this week as he squares off against a Seahawks offense and passing game that has been better at home.

Eric Berry, Chiefs

Matchup: @ Falcons

Ownership: 20%

Berry is having another strong season from an IDP standpoint, and faces the high powered Falcons aerial attack on Sunday, which has been quite accommodating to defensive backs in recent weeks. Get this: In Week 12, the top three tacklers for the Cardinals against Atlanta were defensive backs, including their two starting safeties. That figures to play right into Berry's hand in Week 13 as he will be counted on as the last line of defense to slow the Falcons speedy receivers.

Casey Hayward, Chargers

Matchup: vs. Buccaneers

Ownership: 20%

While other defensive backs have gotten the headlines for their strong play, the NFL’s leader in interceptions (6) is Hayward, who has become one of the most opportunistic corners in the league this season. His fairly low tackle totals over the four games (13 total) have made him an interception dependent play, but the chances should be there for Hayward against Bucs QB Jameis Winston who, despite having a nice sophomore campaign, has also thrown 11 INT including 6 on the road.