It's hard to imagine that many NFL players went through more of an offseason transformation than Garrett Celek.
The college defensive end at Florida State-turned-defensive tackle with the San Francisco 49ers, is now embracing his new role as an outside linebacker.
"I'm still adopting it. I'm still getting used to playing outside linebacker, but so far I like it," Carradine said. "I've still got some learning to do. I'm still watching Aaron (Lynch) and Ahmad (Brooks) and picking up some of their good habits."
Carradine's position change is drastic for many reasons. For starters, a defensive end in a 4-3 scheme is primarily a speed-based pass rusher, usually with a 1-on-1 matchup against an offensive tackle. Playing defensive lineman in a 3-4 defensive scheme requires a player to carry more responsibility as a run-stopper. That means being able to maintain gap control, eat up blocks and let the linebackers behind you make plays.
The move had its physical demands as well. Carradine never played at more than 300 pounds until he entered the NFL.
He's since shed all the extra body mass in order to keep up in pass coverage at his new position. The steep learning curve, however, hasn't stopped Carradine from enjoying the grind of the preseason.
"I feel comfortable," Carradine said. "I'm not 300-some pounds. I'm 270 pounds, back to my college weight. I'm able to play on the outside, set the edge, rush the passer from the outside and cover guys.
"I'm able to do more to help the team, and so I like it a lot."
The linebacker's new skill set was on display in San Francisco's preseason win against the Denver Broncos. With less than a minute remaining in the second quarter, Carradine sacked Mark Sanchez and knocked the ball loose. Nick Bellore recovered the fumble to give the ball back to the 49ers offense before halftime.
On the play, Carradine used a hesitation move to get Broncos right tackle Kyle Roberts off balance. He saw Sanchez step up in the pocket, tossed Roberts to his left and made a play on the quarterback.
Carradine credited his reps against Roberts during the two joint practices for his success in the preseason contest.
"I got a good feeling of what kinds of things they like to do on offense," the linebacker said.
The sack was one of six in the game for the 49ers and one of 11 total quarterback hits.
"We just went with the gameplan and did what the coaches asked us to do," Carradine said. "We were able to go out and make some plays and get the job done."
Pass coverage is still taking some getting used to for Carradine – being able to keep the mindset that your responsibility doesn't end until the whistle blows.
It's about learning the nuances of specific coverages and letting his athleticism do the rest of the work.
"I feel fast," he smiled. "I feel really fast."
Standing up pre-snap opposed to being in a three-point stance also has its advantages. Carradine added a spin move to his pass-rushing repertoire to take advantage of the extra space afforded to an outside linebacker.
He credited Brooks with teaching him the move.
"Watching the other guys spin, I said, 'You know what? I'm going to try that,'" Carradine said.
The second-round pick in 2013 understands that there's a greater sense of urgency for him in 2016. Carradine, who has four sacks in two seasons with the 49ers, will be relied on to contribute this season. He knows the opportunity is there for the taking with Lynch suspended for the first four games.
"I need to play every play like it's my last play and give it all I've got to be able to help the team win," Carradine said.