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Detroit Lions coaching profile: Get to know new defensive coordinator Cory Undlin

A closer look at the Detroit Lions’ new defensive coordinator.

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NFL: AUG 04 Eagles Training Camp Photo by John Jones/Icon Sportswire via Getty Images

With player acquisitions mostly out of the way for the Lions, it’s time to look back and evaluate some of the moves Detroit made this offseason.

Perhaps one of the most important things the Lions did was change defensive coordinators. Whether you believe defensive coordinator Paul Pasqualoni voluntarily stepped down or not, a change was overdue at the coaching position given how much the Lions defense struggled in Matt Patricia’s first two years as head coach. Does Patricia deserve plenty of blame for the issues? Of course. But there needed to be some shakeup in the defensive coaching staff, and it certainly happened this offseason.

Enter Cory Undlin, the former Eagles defensive backs coach. When the hire was first made back in January, fans weren’t very supportive. 62 percent of Pride of Detroit readers gave the hire a C or lower grade.

But before we go jumping to conclusions about Undlin, let’s get to know him a little better in our coaching profile series.

Previously: OL coach Hank Fraley, ST coordinator Brayden Coombs

Coaching Resume:

1998-99: California Lutheran LB coach
2000-01: California Lutheran defensive coordinator
2002-03: Fresno State graduate assistant
2004: New England Patriots defensive coaching assistant
2005-06: Cleveland Browns defensive quality control coach
2007: Cleveland Browns assistant special teams coach
2008: Cleveland Browns defensive backs coach
2009: Jacksonville Jaguars defensive assistant
2010-11: Jacksonville Jaguars defensive backs coach
2012: Denver Broncos quality control coach
2013-14: Denver Broncos defensive backs coach
2015-19: Philadelphia Eagles defensive backs coach

Lions link:

Matt Patricia and Cory Undlin only spent one year together, but it was one in which they immediately created a long-lasting bond. Both Patricia and Undlin had just broken into the NFL—Patricia as a New England offensive assistant, Undlin as a defensive assistant. They shared an office, and got to know each other pretty well.

“We slept in the office together for damn near a year,” Undlin said back at the Senior Bowl. “When you do that, you get pretty close with people.”

After a year with the Patriots, Undlin followed Romeo Crennel to Cleveland, while Patricia stayed in New England to rise up the ranks.

Playing career

Undlin played at California Lutheran University as a safety for four years.

Coaching career

In his first and only year with the Patriots, he saw an organization win a Super Bowl, and just over 10 years later, he would win another one as the defensive backs coach for the Philadelphia Eagles.

In between those times, he found himself always seemed to be working under a defensive-minded head coach. First he followed Romeo Crennel to the Browns. Then he moved onto Jacksonville to learn under Jack Del Rio. Then he moved out west with Del Rio to work with Denver’s John Fox.

The one exception was when he moved over to Philly. First he was under Chip Kelly for a year before Doug Pederson took over. It’s notable that Undlin survived the regime change in Philly, sticking with the Eagles for another four years after Kelly was fired. Then, it was time to work under well-respected defensive mind Jim Schwartz.

So not only is he well-versed in Patricia’s defense, but he’s been around enough defensive minds to bring some fresh ideas to Detroit.

In every step of the way, Undlin managed to work his way up, getting promoted in Cleveland, Jacksonville and Denver. Every time he’s been fired in his career, it’s been because of a complete regime change on the coaching staff.


Is he good?

His reputation really depends on who you ask. Eagles fans were not too happy with the work Undlin had done recently. Michael Kist from our friends at Bleeding Green Nation had this blunt analysis of Undlin, as offered to Lions Wire:

“I have no idea what he does here other than not improve anybody,” was the first line in response to my inquisition. He then provided some context:

“(Undlin) had a great track record before Philly, and I don’t know if Schwartz’s system is just hell on corners.”

But even despite his poor reputation with Philly fans, he was considered to be the top candidate to replace Jim Schwartz if he got shown the door. Hell, less than eight months ago, some Eagles fans were singing his praises for how he dealt with a beat-up secondary in Philly.

And before his time with the Eagles, he worked with some impressive secondaries. Here’s how the defense ranked in passer rating allowed during his years as defensive backs coach:

2008 (Browns): 79.7 (13th)
2010 (Jaguars): 98.5 (31st)
2011 (Jaguars): 83.7 (16th)
2013 (Broncos): 84.5 (17th)
2014 (Broncos): 82.4 (8th)
2015 (Eagles): 92.8 (18th)
2016 (Eagles): 85.7 (11th)
2017 (Eagles): 79.5 (9th)
2018 (Eagles): 93.4 (15th)
2019 (Eagles): 90.8 (19th)

One thing that sticks out is that every place he went, he improved the pass defense his second year. Of course, all that credit shouldn’t go to Undlin himself, but it is an interesting pattern.

He’s also worked with a plethora of elite-talent cornerbacks, including Chris Harris Jr., Aqib Talib, Bradley Roby, Malcolm Jenkins, Avonte Maddox and Champ Bailey.

Player’s coach

No matter who you ask, it seems Undlin is well liked by his players. He brings energy and enthusiasm to his practices and knows how to get along with his players. Here are some testimonials:

Don Carey (via the Detroit Free Press):

“I can tell you he’s going to be an extremely personable dude. He’s definitely going to try to build a bond with the guys.”

“He’s definitely a players’ coach, which I don’t know how that’s going to square with the Patricia mindset. But definitely he’ll be somebody that the guys will trust.”

Malcolm Jenkins (via The Athletic):

“When Cory first got to Philly, all he did was preach press technique. Down to the smallest details, the first steps. That was stuff I was able to learn and actually use on the field. He instantly helped make me a more efficient player.”

Nolan Carroll (via

“He’s on us, he’s on us all the time, making us work,’’ Carroll said of Undlin. “He’s very demanding and that’s been good. He’s also about technique. He always saying technique beats talent. He preaches technique to us every day.’’

But what about the rest of the defense?

Though Undlin’s time in the NFL has been mostly surrounded by defensive backs, he does have experience elsewhere. In Denver as a quality control coach, he mostly worked with the defensive line. He started as a linebackers coach.

That being said, the last time he was a defensive coordinator was 20 years ago.

In his own words:

On his coaching philosophy:

“My coaching style has been the same for a long time. I believe in two things: That is to teach and to demand.”

On his expectations from his team in Week 1

“Sound, tough and we’re going to play as fast as we possibly can.”

On his defensive philosophy:

“My overall philosophy would be whatever the players, whoever is on the roster, what’s the makeup of the defensive side of the ball, let’s do what best fits them,” Undlin said. “How are they going to be successful? Let’s do that.”

Bonus: Here’s video of Undlin—along with the rest of the Lions’ coaching staff—coaching at the 2020 Senior Bowl:

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