Washington Union coach Jeff Freitas said he noticed the change in his 6-foot-2, 200-pound receiver since last season.
"He's just doing all the right things to become a top-flight college player," Freitas said. "He's growing, he's maturing, his work ethic is good. He's doing all the right things in school right now, so as long as he just continues on the path he's on, I see bright, bright things for him."
Greenberry had a big junior season in which he made 66 catches for 1,208 yards and eight scores, then made a name for himself in various high-profile combines and 7-on-7 events. Freitas said he noticed a change in how Greenberry attacks passes.
"I think probably his aggressiveness and eventually going for the football," Greenberry said. "That's a point where I really noticed an improvement. I think competing with high-level players, you have to really be aggressive and try and go get it because not every ball is going to be thrown right where you want it, in a perfect situation.
"He's really become a lot more ball aggressive, and making plays as opposed to his junior year, if the ball wasn't necessarily in a catchable place, he didn't go outside that area to make that play all the time. What I've seen throughout the summer, he's improved a lot in that area."
Freitas added Greenberry is also developing as a leader.
"I ask a lot of my guys, so I'm always asking him to add a little bit more," he said. "He's not the perfect guy yet, but neither are any of the players I'm coaching. I am always asking for a little more out of them, or always trying to build character every day, but he's making big strides. He's heading in the right direction, and I'm proud of him."