ESPN ranks the 6-foot-1, 190-pound receiver as the 14th-best receiver prospect available.
Stills leaves Oklahoma after a tumultuous junior season that saw him assume a much greater leadership role within the wide receiver corps after Ryan Broyles' departure and three returning starters' indefinite suspensions in May.
The arrivals of senior Justin Brown and junior Jalen Saunders, from Penn State and Fresno State, respectively, helped ease some of the pressure on Stills, but he said those summer months in 2012 vastly enhanced his leadership skills.
“I had to lead by example, and not just talk about it, but really be about the things I was saying,” Stills said. “Just for me to be able to take that step and be able to lead a group of guys, and have them put trust me, it really changed me as a player.”
With Saunders; sophomores Sterling Shepard, Durron Neal and Trey Metoyer; and redshirt freshman Derrick Woods, Oklahoma's receiver corps looks like one of the team's strongest units entering the 2013 season, which Stills cited as something that helped make his decision to leave easier.
“I didn't feel like I was leaving the team in a bad position,” Stills said. “I feel like the guys that were recruited and the guys that are there are ready to step up. They're excited. They're probably a little bit sad, as I am, but they're excited to get their opportunity to play.
“I told them when I left, ‘It's your time to shine.'”