It was pretty easy to see the biggest area of improvement for Iowa on Saturday in an impressive 27-17 victory over Arizona: The Hawkeyes’ defensive line, especially end Adrian Clayborn, played much better than it did in the first two games of the season.

The other two layers of the defense – the linebackers and secondary – were solid (and occasionally spectacular) in the first two games of the season and the line also came together in a fairly thorough shutdown of what had been a pretty good offense.

The statistics don’t really tell how well the D-line played although the stats weren’t bad. The Hawkeyes had two sacks, five tackles for losses and four quarterback hurries (three by Clayborn). They’d had only two sacks in the first two games against less talented, more pass-oriented teams.

They also allowed 148 yards rushing (about half Arizona’s season average), with almost none of it coming between the tackles. Most of it came on three plays – a reverse, a quarterback scramble and a draw play in the final minutes against a prevent defense.

All told, it was an important step forward for an area of the team that had to be retooled following the graduations of Mitch King and Matt Kroul.

The many former Iowa players going through their first NFL training camps will see a lot of each other in their opening round of preseason games this weekend.

Shonn Greene and Matt Kroul, both with the New York Jets, will make their debut Friday night against the St. Louis Rams and former Hawkeye cornerback Bradley Fletcher.

And Saturday’s Tampa Bay-Tennessee game will match center Rob Bruggeman against defensive tackle Mitch King.

Bruggeman, who signed with Tampa Bay as an undrafted free agent, was not regarded as one of Iowa’s best pro prospects, but he may be a starter in his NFL debut. Veteran centers Jeff Faine and Sean Mahan are battling injuries and Bruggeman has been working with the Bucs’ No. 1 offensive unit in practice, according to the Tampa Tribune.

“I’m just going to try to go out there and learn from everything that’s going on,” Bruggeman told the Tribune. “I’m going to be stepping into my first preseason game in the NFL, so I’m sure I’m going to learn a lot of things real quick when I’m out there. I’m just stepping in here, so I’m trying to learn what’s going on and learn from everybody else.”

Things haven’t been going as well for King, a former Burlington star who also was undrafted. He missed two days of workouts because of an illness about a week ago and is listed on the fourth team on the depth chart for Tennessee, which has 13 defensive linemen in camp.