While not an explosive tackler, he does a very good job dragging ball-carriers to the ground using his length. He needs to sink his hips instead of tackling shoulder pads and must improve his angles to the ball against quicker runners, but he has a knack for exploding into running lane and can smother underneath throws in zone coverage.
Heeney is smart enough not to get sucked in by play-action, and is fast enough to recover from a false step, as he has the straight-line speed to hustle downfield and chase to the sideline. He attacks and slides by fullbacks coming out of the hole, knifing through gaps when attacking stretch plays.
Heeney has a decent blend of speed, quickness, change-of-direction agility and flexibility. He is a normal strider who flashes a good closing burst on the ball and has the agility to pursue on the outside and the hip flexibility to drop off in pass coverage. He is good when trying to read and react to keys, as he seems to see the big picture and gets around the ball. When he locates the pigskin, he shows no hesitation to attack the ball, but there is some wasted motion when he has to drop off in pass coverage.
Heeney seems to be a better tackler when working inside, where there are bigger blockers that he has to deal with. He has functional strength for tackling, but is best when he makes plays in front of him, as he shows better explosion to strike and wrap. Rarely does he miss a tackle when he takes a good angle to the ball. He can fill the rush lanes quickly and does a nice job when asked to hold and control at the point of attack. His low pad level allows him to slide by fullbacks coming out of the hole, knifing through gaps when attacking stretch plays.
The Kansas linebacker quickly diagnoses plays and can sniff out screens. Despite playing a position where he operates with a take-no-prisoners approach, he is actually a disciplined player who rarely bites on play action. He might lack the size and strength needed to hold his own in phone booth at the NFL level (19 reps at the 225-pound bench press and stands 6:002 and has just 30 3/4-inch arm length). However he is relentless in pursuit and will lay his body on the line if it means he can make the tackle.
Heeney has impressive speed and he takes proper pursuit, demonstrating the loose hips to make plays from sideline-to-sideline. He’s a fluid athlete that's smooth changing directions and flashes the ability to recover when gets caught out of position. As a between-the-tackles defender, he wraps up and does a nice job of getting ball carriers to the ground once he latches on.
With his timed speed, his explosiveness allows him to penetrate the backfield to deliver the big hit, demonstrating the same consistency in the open field as he does when working in close quarters. As a pass defender, he shows good awareness and does a nice job of locating crossers when asked to drop into zone coverage.
As a former prep running back, he is savvy enough and fluid enough to match up with most backs and tight ends in man coverage. He generates above-average closing speed for a “Mike” guy (4.59 in the 40-yard dash/1.61 in the 10-yard dash) and he can get to the quarterback when asked to blitz, doing so with good aggression (34 tackles behind the line of scrimmage as a Jayhawk).
Heeney possesses the hip flexibility and speed to close on plays coming from the backside and he displays very good football intelligence. He can quickly diagnose a play and figure out where it’s going. When he gets a gap, he’s very good at disrupting the pocket, but I would not consider 4.5 sacks in 46 games as him being a valid pass rusher.
Heeney works well to the inside despite his lack of strength, as he can “out-quick” running backs to close on the quarterback. He’s smooth in his pursuit and fluid moving in space, as it is obvious from film evaluation and his performance at the 2015 NFL Scouting Combine that he has the speed to track down ball carriers.
Where he needs to improve here is in the angles he takes, as perhaps to compensate for the rest of his defense’s struggles, there were times when he lacked discipline in his pursuit the second half of the 2014 campaign. As a run stuffer, he moves around with ease thanks to his speed and agility. He has the range to stop the run from all sides of the field, but is still learning how to uses his speed to recover when he takes poor angles.