A fifth-round draft pick by the team in 2012, Greenwood entered the offseason program a year ago around this time with a ton of raw potential.
The Lions fell in love with the former Albion College star's 6-foot-1, 195-pound frame and sub 4.4-second speed during a pre-draft workout.
Greenwood was rough around the edges, but the Lions were hoping he was a fast learner in organized team activities (OTAs) and training camp and his length and athleticism could help them in 2012.
A torn abdominal muscle in OTAs last year and the subsequent surgery changed all those plans, though. Instead, Greenwood spent the entire year on PUP.
Now, almost a year since the injury, Greenwood is back to 100 percent and fervent to show what he can do.
"I'm very eager," Greenwood said Monday.
More than anything, he said he wants to make good on the Lions taking a chance on him last year.
(Sitting out a year) gives me a level of unexpectedness," he said. "When I'm able to show what I can do, then people will realize what I bring to the table."
But what is that exactly?
"I feel (my length) allows me to compete," he said. "These receivers out here are big and fast and I just feel like I almost have that same body shape and body frame. It's better for matchups, as far as what I'm able to do competing against receivers."
The only time Greenwood has stepped on the football field since his last college game Nov. 19 of 2011 was during a three-week period in the middle of last season when he was allowed to practice as the Lions decided whether to activate him from PUP.
"It was good for me," Greenwood said of the practice time. "It was my learning experience. Learning what to do and not to do and how my body felt against a different level of competition."
Greenwood says that experience -- along with all the time in the film room and meeting rooms during the course of the season -- has made him better.
"I think I'm a lot better," he said of where his game is now compared to 365 days ago. "I've learned a lot of technique stuff. I've learned a lot of scheme-oriented things. The game has slowed down."
He's been 100 percent the entire offseason and says his eyes are set on a starting cornerback spot. There's plenty of competition for the vacant right cornerback spot from the likes of
"It was around this time last year I got hurt," Greenwood said. "Just to be back in the swing of things is great. Definitely excited to get out there and start competing."