A few months ago, Kyle Shotwell was an All-Everything player.

He was the big man on campus at Cal Poly-San Luis Obispo, an award-winning middle linebacker on the football team who stopped running backs, receivers and quarterbacks.

He was the leader of a Mustang defense that posted three shutouts and finished the regular season ranked sixth in the nation for NCAA-Division I-AA schools in total defense, third in pass defense, fourth in sacks, fifth in tackles for lost yardage, and 10th in scoring defense.

He was a First-Team All-America selection by The NFL Draft Report and The Sports Network, the Defensive Player of the Year in the Great West Football Conference, and the Northwest Region Linebacker of the Year by Football Gazette.

He was also the recipient of the Pat Tillman Award for his performance in the East-West Shrine Game and an All-America First-Team selection by Football Gazette.

“I got a complete college experience,” Shotwell said. “The quality of people that Cal Poly brings in is just second to none. I got a great education, but at the same time I played at a high level of football, had a lot of success with it, and made a lot of long-lasting relationships with guys that I’m going to be friends with forever.”

As he headed from the fieldhouse at Redwood Middle School to his hotel room at the Napa Valley Marriott late Monday morning, Shotwell acknowledged that he’s now an underdog. He’s an undrafted free agent rookie in the Oakland Raiders training camp and is working with the third defense at weakside inside linebacker. He’s also a backup on special teams, running with both kickoff and punt teams.

Shotwell, who is from Santa Barbara, participated in mini camps and organized team activities during the offseason at the Raiders’ complex in Alameda. But upon arriving in Napa last month, he was welcomed with a whole new set of challenges — the biggest of which is comprehending everything from a mental standpoint.

“What I didn’t expect was how mentally draining it is, because of the fact that you’re learning a new playbook, a new system, new terminology — just learning,” said Shotwell. “Then the fact that we spend a lot more time in meetings. The days are just longer. A typical day starts at 6:45 a.m. and we don’t go to bed until about 11:15 p.m. It’s pretty much just football all in between there.”

Shotwell — who ranked eighth nationally and led the team and league with 122 tackles (62 solos) last year — is all about football. He takes the field trying to make the most of every opportunity and situation he’s put into. With his family looking on at Saturday’s intrasquad scrimmage, Shotwell made a tackle on a running play.

“I had a couple of decent plays,” he said. “I didn’t do anything that stood out. It was good just to be in there.

“I really feel like the game’s starting to slow down for me a little bit. It’s really only been the last couple of days where I’m starting to really understand the defense and starting to understand where I fit in.”

It’s been a summer of adjustments for Shotwell (6-foot-1, 240 pounds), who after playing in Cal Poly’s double eagle flex defense is now learning about the Raiders’ 4-3 base.

“The first couple of days were pretty hard,” he said. “I was struggling. But I think I’ve been able to adjust, taking one day at a time and pressing through it. I knew it would be physically challenging. But the mental aspect is something that I’ve had to work hard to overcome.

“It’s more the pressure that you put on yourself — the pressure that’s put on you is more just yourself and wanting to succeed. Obviously, the coaches want you to succeed — otherwise they wouldn’t have brought you in here, they wouldn’t have signed me as a free agent. They’d like to see me make it. But at the same time, if you don’t make the most of your opportunities, then they’re just going to go to the next guy. That’s where I think the pressure lies.”

Shotwell was Cal Poly’s third consecutive winner of the Buck Buchanan Award, presented to the nation’s top defensive player in the NCAA Division I Football Championship Subdivision (formerly I-AA) by The Sports Network. He completed his Mustang career with 392 career tackles to rank No. 2 all-time at the school.

Shotwell had seven sacks last year and 17.0 for his career, scoring his first Cal Poly touchdown in the final game of his career on an interception return. He had seven total tackles in the East-West Shrine All-Star Game at Reliant Stadium in Houston last January. Last year’s Cal Poly team finished 7-4, beating Savannah State in the finale, 55-0, posting the school’s fourth straight winning season and a No. 14 national ranking.

He also participated in a Pro Day at Cal Poly in late March and ran the 40-yard dash once in 4.56 seconds, the short shuttle in 4.42, and the three-cone drill in 6.94. He also had a 35.5-inch vertical jump, a 10-foot, 1-inch broad jump, and did 23 bench presses.

When he’s not on the field for one or two practices daily, he’s in meetings or studying the playbook.

“It’s not an easy road. It’s a humbling experience. It’s tough and challenging. Coming out of high school, I was the big man on campus. I had to prove myself in college, earn my spot and earn my way. I was fortunate enough to have some success. Now I’m hoping to do the same thing here. You’re at the bottom of the totem pole — I’m just trying to work my way up. I have to give it my all every day.

“I definitely view myself as the underdog. It’s hard. But those times where you’re the underdog it makes you appreciate it when you do make it and you make it to the top. I definitely feel very blessed and fortunate. The people that I’ve been able to meet these last couple of months and the things that I’ve been able to do are just really fun. The schedule is demanding. I can’t imagine another job that I’ll ever have that will be this physically and mentally straining and demanding. I’m trying to do everything that I can in my power with stretching and eating right to make sure that I can stay injury-free. It’s a little bit of luck.

“If you can push through this, I think you can push through anything. It’s training me not only to be a better football player, but a better man as well. It will pay off in the long run. I hope to be successful and use the lessons that I’ve learned here to carry on. I’ve got a lot of people wishing me the best — I couldn’t do it without them.”

This is a big week for Shotwell. On Thursday he’ll participate in the Raider Nation Celebration at McAfee Coliseum in Oakland from 4 to 8 p.m. On Saturday the Raiders open their preseason schedule against the Arizona Cardinals.

“I’m just looking to go out there and fly around and hopefully catch some people’s eyes and hopefully stick. I hope to get in there and prove that I can play with these guys. These preseason games are going to be really big for me to get in there and to see what the speed of an NFL game is like.

“I just want everyone to see that I give 100 percent effort — that’s the only thing I can control. I want people to realize that I’m the type of guy who’s going to give it their all and that they can count on me to be there.”

Shotwell also played at Dos Pueblos High School-Santa Barbara and was All-CIF Southern Section Division IV, All-Santa Barbara County and Los Angeles Times All-Section Team honors as a linebacker and running back.