IOWA CITY | To suggest Reese Morgan is working with a young group of defensive linemen this spring is not an understatement.

“Four of the guys we are working with right now were picking out tuxes for prom a year ago at this time,’’ the Iowa defensive line coach said Wednesday.

And those four players aren’t the only ones searching for the right fit.

Two-thirds of the way through spring practices, Morgan still finds himself looking to put the right pieces in the right places on a defensive line which struggled to develop an effective pass rush as the Hawkeyes played their way to a 4-8 record a year ago.

Iowa recorded just 13 sacks in 12 games last season and Morgan knows that finding ends with the ability to chase down quarterbacks is among his top priorities.

“When we get the green light to go ahead with pass rush in a game, we have to get there,’’ Morgan said. “That’s an area where statistically we have to improve upon, technique-wise, fundamentals, emphasis-wise, everything.’’

The depth chart remains fluid at all four defensive line positions and Morgan expects the Hawkeyes to again rotate a number of players, preferring to keep fresh bodies on the field against the wide-open attacks Iowa faces more frequently.

There is some experience. End Dominic Alvis and tackle Louis Trinca-Pasat started all 12 games a year ago although Trinca-Pasat watches from the sidelines this spring as he recovers from offseason rotator cuff surgery.

There is also plenty of youth. Redshirt freshmen Faith Ekakitie, Jaleel Johnson and Daumantas Venckus-Cucchiara and sophomore Drew Ott were all members of Iowa’s 2012 recruiting class and all are on the two-deep depth chart this spring. Ott was forced into action at an end position for the final five games last season because of injury-related depth issues.

“Now, those guys are going to be on the field for us this fall,’’ Morgan said. “We have a few other guys who have been around here for a couple of years, too, we need for them to take that next step.’’

Morgan likes the growth he has seen this spring from junior tackle Carl Davis and sophomore tackle Darian Cooper, who join Riley McMinn and Mike Hardy on the spring depth chart.

But, he continues to search for consistency as that group continues to develop.

“We all realize that we have to get better and I think we’re all pushing each other to make that happen,’’ Cooper said following Sunday’s open practice in West Des Moines. “This is the time of year when guys establish themselves, put yourself in a position to win a position in August and we’re all working on that.’’

Morgan’s work continues as well, including plenty of experimentation which led Ekakitie from tackle to end for the first time in Sunday’s practice.

That type of movement has been a regular occurrence this spring and Morgan likes versatile players who can fill multiple roles, pointing to Hardy as a player who has also shuttled between tackle and end. He calls Ekakitie a player with “some unique abilities’’ who simply lacks experience at this point.

Finding a way to put those abilities to work is what Morgan is up to now.

“At end, you have to be able to get off the block, line up on the tight end, make sure you hit him. If he doesn’t release, you release him, then you take on the tackle and then pressure the quarterback and you do it all in two and a half-to-three seconds,’’ Morgan said. “We’re asking a lot of guys, but they are responding and that is encouraging.’’