"Just a little bit of time could mean a whole lot of draft money."
Kelly, who measured in at 6-foot-4 and 227 pounds, reached 32 inches in the vertical jump and 9 feet, 9 inches in the long jump. He posted times of 4.24 in the short shuttle and 7.00 in the three-cone drill.
Kelly looked sharp running routes and catching the ball during receiver drills.
He is flying to Cincinnati to meet with Bengals personnel later today.
Bengals offensive coordinator Bob Bratkowski was among the more than 30 coaches and scouts who attended OU's second pro day, which included former Sooner defensive back Reggie Smith, tight end Joe Jon Finley and cornerback Marcus Walker.