Study hard, play hard and fast.

That could serve as a motto for the Detroit Lions' linebackers.

As the offseason workout program winds down with mandatory minicamp this week and the last OTA sessions next week, they will finish up what amounts to summer school learning the principles of head coach Matt Patricia's system. 

With a largely veteran group of 10 linebackers, assistant coach Al Golden has found that the learning curve was shortened by players eager to learn.

"It's a highly intelligent group," Golden said. "It's made the competition tighter. We have a lot of guys with experience in the system, and a lot of guys with NFL experience.

"It's a thinking man's defense. What they're embracing right now is not the route memorization but the conceptual application. If you don't do that, or you fail to do that, I think you'll struggle in this system."

No one should get the impression that Golden is trying to develop a group of bookworms and robots who follow their notes to get from point to point on the field.

The concept of the defense is just the opposite. The goal is to learn the assignments to a degree that they can perform without thinking and rely on instincts.

"If you're just rigid and, 'OK, tell me where to go and what to do,' I think that's a little inconsistent and incongruent with this system," Golden said. "This system is about problem solving and being able to think on your feet, and being able to react to certain things."

Jarrad Davis, a first-round draft pick last year, is the only holdover starter in the group. Also returning are three primary backups – Jalen Reeves-Maybin, Steve Longa and Nick Bellore, who was at fullback for the only OTA open to the media.

Three veteran free agents were signed – Devon Kennard, Christian Jones and Jonathan Freeny, with Kennard the most likely of the three to start based on his 35 starts in four seasons with the Giants.

Signed as free agents were rookies Al-Rasheed Benton and Chad Meredith, and Trevor Bates, who was on the Giants' and Patriots' practice squads last year.

Golden shifted to coaching linebackers with the Lions this year after two seasons with the tight ends, but he is not new to the position or the system.

In college he coached linebackers at Boston College and Penn State, and he was defensive coordinator at Virginia under head coach Al Groh, whose defense was based on what he learned as a Giants assistant under Hall of Fame head coach Bill Parcells.

The Parcells coaching tree produced Patriots head coach Bill Belichick, who in turn had Patricia as an assistant and defensive coordinator.

The disciples of that system have added their own nuances over the years, and Golden has seen how the defense he coached at Virginia from 2001-05 has evolved under Patricia.

"It's interesting to see the finger prints Matt has put on that," Golden said.

"From a player's standpoint, this is a linebacker-friendly defense. It's a multiple defense. It's not rigid. I think they're embracing the whole process at this point. The football part is one part of it. Really, everything we're doing is starting from a new standpoint.

"There's a little nuance to how we're teaching things. There are not many exceptions to it. It's a high standard, and that's what we're trying to follow.

"The linebackers are obviously the conduit between the front (defensive line) and the back end (secondary). When things change or are shifting, a lot of times they have to fill in and be able to move and be versatile.

"I think the linebackers are a big part of that."