IOWA CITY, Iowa (AP) — Iowa’s defensive line needs to be rebuilt, its secondary has holes to fill in key spots and all the defensive coaches have switched spots. Now’s as good a time as any for the Hawkeyes’ promising linebacking corps to step up and lead a defense that failed to meet lofty expectations in 2011. Much of Iowa’s hopes for a defensive turnaround this fall rest of the development of its linebackers. The Hawkeyes return a pair of starters in juniors James Morris and Christian Kirksey, who’ll be joined by fellow junior Anthony Hitchens in what should be the strength of a defense that slipped from seventh nationally in scoring defense in 2010 to 46th a year ago.