Flash back to the preseason.

Defensive coordinator Phil Parker called his defensive line group the best he’s had during his 19-year Hawkeye tenure.

That’s a lot of hype for a relatively young group of players.

Through six games, I’m not so sure they’ve lived up to the buildup; the defensive line has gotten the job done and at times looked stellar, but the consistency isn’t there — yet.

Looking at the numbers, sophomore defensive end Anthony Nelson leads the team with 5 sacks — one shy of his season total from 2016. He’s also recorded 6 tackles for a loss, broken up 2 pass attempts, and forced a fumble.

If anything, Nelson has been one of Iowa’s most consistent pass rushers.

Freshman A.J. Epenesa has flashed his potential here and there, giving Hawkeye fans a glimpse of his raw athleticism in only his first year in a Hawkeye uniform.

In the opener against Wyoming, Epenesa notched a sack on potential NFL-first-round quarterback Josh Allen.

“He’s still trying to figure it out totally, but, boy, he goes hard and has a great attitude,” head coach Kirk Ferentz said after the game. “He’s fun to have on the field.”

Epenesa is still figuring things out, but slowly he’s getting a grasp on the defense. He’s got 2.5 sacks (tied for second on the team), 2.5 tackles for a loss, and he’s forced a fumble, too.

But aside from Nelson and Epenesa, Parker Hesse is the only other lineman who has done considerable damage this season.

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So far he only has 1 sack, but he has 6.5 tackels for a loss — second best on the team and one fewer than his 2016 total — an interception (the only other Hawkeye lineman with an interception is Brady Reiff), and a team-high 2 forced fumbles.

Matt Nelson, who has played all over the line this year, has yet to make a significant impact. He’s another long-armed defensive lineman who has batted down a pass at the line of scrimmage, but compared with his 5-sack, 6-tackle-for-a-loss 2016 campaign, this season hasn’t been the same.

Nathan Bazata adds in 20 tackles (1.5 for a loss) and 0.5 sacks. Cedrick Lattimore is the only other linemen to find the sacks column, notching 0.5 through six games.

In Iowa’s 21-19 loss to Penn State on Sept. 23, fans saw the highs and lows of the defensive live. Anthony Nelson (2.5 sacks), Epenesa (1 sack), and Lattimore (0.5 sacks) all got to the quarterback at some point during the contest. The defensive line registered 7 tackles for a loss as well.

But there were times in which Penn State ran a read option — quarterback Trace McSorley read the defensive line and determined whether to hand the ball off to running back Saquon Barkley or take it himself. While the linebackers’ reads affect these plays as well, the Nittany Lions torched Iowa for most of the game this way.