No reward comes without a little risk. The improvement of the Dallas Cowboys’ defense in 2015 will rely on the reward they reap from signing Rolando McClain and Greg Hardy.

Hardy, of course, signed with the Cowboys two weeks ago. Earlier this week, McClain, who probably had the biggest impact on the Cowboys’ defense a year ago, signed a one-year deal with the Cowboys for $3 million, which can balloon to $4 million with incentives.

Hardy signed a similar deal, though his incentives could push the deal to nearly $12 million in 2015.

The reward is obvious. If the pair performs the way they’re expected to, they’ll be worth the money and improve a unit that, while spunky a year ago, still had an anemic pass rush and was ranked No. 19 in total defense.

McClain came to Dallas just before training camp a year ago and, after working himself into shape, became the team’s savior at middle linebacker in the wake of Sean Lee’s injury. Injuries wore him down late in the year, but for the first three months of 2014, no defender was more important to the Cowboys, as he wrapped up the season with 81 tackles and a sack, plus two interceptions.

McClain will stay in the middle in 2015, and the now-healthy Lee will move to the weak side. A Lee-McClain combo at linebacker should be intriguing and make the defense better.

Hardy should give the pass rush a jolt, one that produced only 28 sacks and saw Jeremy Mincey lead the team with six. If quarterback is the game’s most important position, then the right defensive end is the game’s second most important, as that player brings pressure to the quarterback from his blind side.

If you can’t pressure the quarterback, it’s awfully hard to win games, and the Cowboys’ formula for a 12-4 season last year worked as much as possible to mask that deficiency. Before last season, Hardy had 34 career sacks.

The risk is also obvious, given that both McClain and Hardy were signed for well below market value, and neither was courted in the crazy opening days of free agency. There are reasons they accepted small base salaries and incentive-laden deals. Choices they made limited their options.

McClain faces a four-game fine for violating the league’s substance abuse policy for a third time. No one is sure what McClain tested positive for, only that it could cost him one-quarter of his 2015 salary, pending appeal.

The money isn’t as big a deal as what could happen next if McClain tests positive a fourth time — a four-game suspension. One imagines the Cowboys have done their research, know what caused the test and have assurances that it won’t happen again. But that positive test has hung around McClain like a noose this offseason. The only other team willing to talk with him was New England.

Of course, that pales in comparison to Hardy, who could miss time this season due to an NFL suspension related to his court case in North Carolina last year. Hardy was convicted of assaulting his then-girlfriend, Nicole Holder, in a bench trial. That led to Hardy’s missing all but one game of last season when the Panthers put Hardy on the league’s exempt list. (The Panthers say that was Hardy’s decision.)

The conviction was overturned on appeal, as Hardy reached an out-of-court settlement with Holder, and she stopped cooperating with the prosecution. The NFL is now reviewing the case to determine the suspension, including a request to see the photos of Holder after the assault. If you’ve read Holder’s testimony, you know she left little to the imagination.

Due to that, Hardy was practically toxic during free agency. Hardy will likely miss game time, and it could be up to six games. That’s part of the reason the bulk of Hardy’s deal is incentive-based. The Cowboys will spend the season waiting for the other shoe to drop — not just for Hardy’s suspension but also to see if he’s changed. No guarantee there.

If you’ve followed the Cowboys long enough, you know owner Jerry Jones loves a good reclamation project. Well, he has two this season. He thinks the risk is worth the reward. In fact, he’s staking his season on it.