When South Dakota ran off six straight wins to start the 2017 season, including a trio of victories against Top 25 teams, the Coyote defense was stingy - allowing more than 30 points in only one game.

But all of that changed in the second half of the season as USD dropped five of seven, allowing 30 or more points six times.

Those late struggles have raised a number of questions for the 2018 Coyotes, which is one of reasons why USD was picked to finish in the middle of the Missouri Valley Conference pack, despite making the FCS Playoffs and winning a first round game last season.

Overall in 2017, the Coyotes were eighth in total defense in the Valley, seventh in points allowed.

The biggest struggles came against the pass, where USD allowed nearly 265 yards a game, next to last in the league.

The issues in the secondary are understandable when you consider that injuries and suspensions led to players in new positions and underclassmen getting playing time they hand't counted on.

But the challenges of 2017 may translate into a silver lining for the 2018 Coyote secondary with a group of young, talented, and now experienced players returning for new defensive coordinator Brian Mohnsen.

Mark Collins and Isaac Armstead were the biggest beneficiaries of the extra playing time, combining for four interceptions.

At safety, last season's leading tackler Andrew Gray, along with Mike Johnson, and Phillip Powell all have starting experience.

Up front, the Coyotes return two of the best defensive ends in the Missouri Valley.

All-Conference end Darin Greenfield led the league with 19.5 tackles for loss last season, while recording a team-high nine sacks. He's book ended with returning starter Kameron Cline, who stands 6'4.

In the middle of the line, the Coyotes have a host of underclassmen who will have a chance to nail down a starting spot.

Two starters return at linebacker, seniors Alex Gray and Alex Coker. Sophomores Jack Cochrane and Joe Kordus are strong contenders for starting spots this season.

Mohnsen's defense will feature some new wrinkles in 2018. The word 'multiple' has been used quite often during spring and fall camps to describe the approach, which means the Coyotes will present a variety of different looks this season.

I talked with Darin Greenfield about how the USD defense is progressing heading into the 2018 season: