When the 4 1/2-month lockout ended last week and the linebacker out of the University of Oregon reported to the NovaCare Complex to pick up his playbook before heading up to Lehigh, defensive coordinator Juan Castillo called him into his office and informed him that he was going to be taking the first-team reps at middle linebacker.
"He said you'll be running with the ones," Matthews said. "As a rookie coming in, not every rookie comes in and gets to play right away. I was definitely shocked.
"It was a good feeling at first. Then a little intimidating being up in front of the huddle [making the play calls]. But the more I did, the more comfortable I got. I feel natural at it. I think they're comfortable with me. I'm just looking forward to the challenge."
It's too soon to say whether Matthews will be the Eagles' starting middle linebacker in 6 weeks when they open the season in St. Louis against the Rams. But less than a week into camp, he's given no indication that the job is too big for him.
Considering the significant investment the Eagles have made in their defense the last few days with the additions of cornerbacks Nnamdi Asomugha and Dominique Rodgers-Cromartie and defensive linemen Jason Babin and Cullen Jenkins, some might question the wisdom of inserting a rookie at middle linebacker.
But this is no ordinary rookie. This is the youngest member of the NFL's royal family. Brother of two-time Pro Bowl linebacker Clay III. Son of Clay Jr., who spent 19 years as an NFL linebacker. Grandson of Clay Sr., who also was an NFL linebacker. Nephew of Hall of Fame offensive lineman Bruce.
"Imagine being him and sitting down for dinner since with that family since he was a kid," Castillo said. "Imagine what they've been talking about all their lives. He couldn't help but learn a lot just sitting there. I would've liked to sit at that table and had dinner with them.
"We just felt he had the right qualities to be the MIKE [middle] linebacker."
The Eagles didn't necessarily draft Matthews because of his last name. But it certainly didn't hurt. Good genes and all that.
The 6-1, 230-pound Matthews doesn't have the extraordinary physical ability of his brother. But he's a smart, instinctive player who has a knack for always being around the football.
It's possible the Eagles will eventually bring in a veteran middle linebacker. But for now, they seem to want to give Matthews as many snaps as possible and see how he does.
When the Eagles didn't attempt to re-sign last year's starting middle linebacker, Stewart Bradley, it was assumed that Jamar Chaney, who played pretty well at the MIKE spot after Bradley dislocated an elbow in December, would replace him. But you know what you do when you assume.
What Castillo did instead was slide Chaney over to the strong side, move strongside linebacker Moise Fokou to the weak side and insert Matthews at MIKE.
The lockout, which wiped out spring minicamps and OTAs and robbed rookies of valuable learning time, was supposed to make it difficult for many first-year players to make significant contributions this season.
Maybe Matthews is the exception. Despite not getting his first peek at the Eagles' defensive playbook until about 44 hours before he stepped on the field here at Lehigh, Matthews has picked up everything fairly quickly.
"It hasn't been as tough as I thought it would be," he said. "I got a quick basic understanding of what we were doing and went from there. It hasn't been too complicated. You just have to keep up.
"It's all about learning the new terminology. I feel like I'm picking it up pretty quick. I'm getting the hang of things."
The MIKE linebacker is responsible for getting the play from the sideline and relaying it to the rest of the defense. For a rookie, that can be intimidating. But Matthews has handled it well.
"I never had to stand up in front of the huddle at Oregon," he said. "But it came pretty natural. It's really not that hard."
Said Castillo: "Casey is very smart, very calm. He doesn't get nervous, doesn't get excited. He just waits for me to make the call. He's just a very confident individual."
Matthews has impressed the Eagles' defensive veterans with his composure and how quickly he has picked up the defense.
"He's still learning," defensive tackle Mike Patterson said. "But we feel comfortable with him out there and that's all that matters. He takes charge when he needs to. He acts like he's been there before."
In a way, he has been. Through his brother, through his father, through his grandfather and through his uncle. He is not your typical deer-in-the-headlights, fourth-round rookie.
"When he was coming out [of Oregon], everybody wanted to compare him to his brother," NFL Network analyst Mike Mayock said. "He's not his brother. But he's a very good football player.
"From an instinct perspective, he's impressive. He's a hard worker. He's always around the ball. If you're asking me whether I think he can step in and make the play calls and play as a rookie, the answer is yes."
Former NFL offensive lineman Brian Baldinger, also an analyst for NFL Network, echoes Mayock's sentiments.
"He can really get to the ball," he said. "I was talking to [Oregon coach] Chip Kelly not long ago. He said [Matthews'] first day at Oregon, he's out there [running] second- or third-team or whatever it was. [The offense] ran a bootleg and Casey immediately read the boot and hunted up the crossing route like he had been doing it forever. Nobody had told him. I think it's just the DNA."
For more Eagles coverage and opinion, read the Daily News' Eagles blog, Eagletarian, at www.eagletarian.com.