NFL.com posted a list of the top 14 "most explosive athletes in college football" for the 2014 season.
Here is what they said about Gregory:
Gregory led the Big Ten last season with 9.5 sacks and was fourth with 16 tackles for loss. He is a speedy force off the edge (he has been clocked as quick as 4.67 seconds in the 40) who could stand to get a bit stronger. But his pass-rush abilities definitely already have drawn the attention of NFL scouts. Gregory had nine sacks in 2011 as a true freshman at Arizona Western Community College but missed the 2012 season with a broken leg and still is learning how to be a well-rounded defensive end. Gregory is from the Indianapolis area -- he signed with Purdue as a 210-pound defensive end out of high school but was an academic non-qualifier.
While just a junior, many feel Gregory could move on to the NFL with a similar 2013 season.