Wide receiver J.J. Nelson, shown here catching a punt, could be key in improving the Cardinals' return game

J.J. Nelson is not faster than a speeding bullet. That's impossible. But slower-moving bullets may want to check their rearview mirror, just in case.

The Cardinals' fifth-round draft pick had the best 40-yard dash time at the NFL Scouting combine in February – clocked at 4.28 seconds – and showed it off last season at Alabama-Birmingham, averaging a nation-high 38.3 yards per kickoff return with four touchdowns.

Those blazing wheels have made Nelson the prime candidate to do kickoff and punt returns for the Cardinals in 2015, and the first time he hits top gear at training camp should be appointment viewing.

Fast return men, though, are nothing new. The Cardinals had Ted Ginn last year, a gazelle in his own right, yet lost a yard on their kickoff return average from 2013.

A 2011 rule change moved the kickoff up to the 35-yard-line, increasing touchbacks and putting more pressure on the return men to choose correctly when bringing the ball out of the end zone. Thus far in Bruce Arians' tenure in Arizona, the Cardinals haven't had much luck. While last year's punt return average made a nice leap, the Cardinals finished last in the NFL in kickoff return average (19.0) after finishing tied for last in 2013.

"Not that we haven't worked it, but we're sitting here two years later and I haven't gotten the results I've had before," special teams coach Amos Jones said. "I've got to look at myself – the little things that I might have taken for granted won't be that way now."

Jones worked as a special teams coach for the Steelers from 2007-2012. In his final four seasons before joining the Cardinals, the kickoff return unit averaged 24.3 yards per return, finishing in the top half of the league each time and ninth or better in three of the four years.

Jones said he wants to re-emphasize the notion of attacking vertical seams like his units did in Pittsburgh. While returns designed to hit the edge can pay off handsomely in the right situations, there are also many times when they get stuffed quickly.

"If you spend too much time going east and west, you're going to get stuck and give everybody a chance to get an angle," said wide receiver Brittan Golden, another return candidate. "You're in the NFL. Everybody's fast."

Said Jones: "Ain't nothing wrong with putting it out on the 25- or 30-yard-line by hitting it downhill."

When the Cardinals returned for workouts in April, coach Bruce Arians told them he wanted more starters on special teams in 2015, according to cornerback Patrick Peterson. While it heightens the injury risk – safety Tyrann Mathieu and wide receiver Teddy Williams both suffered season-endin

g injuries on special teams in 2013 -- it's also an important facet of the game.

Peterson, who had four punt returns for scores in 2011, said he was flanked by starters blocking for him that season.

"We had a lot of vets, a lot of starters that understood what punt return meant: This can be a game-changing play right here," Peterson said. "I'm not bad-mouthing the rookies, but they don't quite understand the importance of punt return, kick return, kickoff coverage, all that stuff. Like coach said, I think we need to get more starters on those units, and we'll be more successful than we have been over the last couple years."

The investment of a fifth-round draft pick on Nelson is another sign the Cardinals are taking special teams seriously, and the addition could be a boon if his electric exploits in college translate to the pros. Jones knows the return game has struggled the past two years, but believes it has the chance for improvement with some fine-tuning.

"I've got to do a better job, because if I don't look at myself first, I can't look at them," Jones said. "They've got to do a better job. We've all got to have a little bit more intensity about it. We've had that a good bit this spring… High intensity, high technique, and then if we throw those eight penalties out (which brought down last year's average), we've got a heck of a lot better chance to have some positive yards."