Kansas suffered one major hit from its surprisingly dominant defense of a year ago. And we're not talking Aqib Talib, although we'll get to him shortly. At issue is the loss of coordinator Bill Young, who left for Miami, responding to Randy Shannon's plea for help. Clint Bowen might yet prove capable as Young's promoted replacement. Know this, Young did leave behind a loaded defense, featuring a back seven more stout than any in the Big 12. Last week, we hailed KU's linebackers as the league's best. Ditto for the Jayhawk secondary, despite the loss of Talib, the 20th overall pick in the NFL Draft by the Tampa Bay Buccaneers. There's no one to match Talib's combination of instincts and skill, but there's talent and depth and experience, with three starters back plus two more players who recorded significant minutes. Chris Harris started 10 games at a cornerback spot as a true freshman and was named Big 12 Defensive Newcomer of the Year. Darrell Stuckey and Patrick Resby are returning safeties. Kendrick Harper, expected to assume Talib's vacated corner spot, rotated with Harris a year ago. Safety Justin Thornton, who tied Talib with a team-high five interceptions, is pushing to break into a starting role. The secondary — combined with the linebackers — are a major reason the Jayhawks continue to garner major support as a budding force, rather than a one-year fluke. KU opened at No. 13 in the coaches' Top 25 released Friday. Not everyone's convinced. "I think they have pressure to continue that kind of success,” said Colorado safety Ryan Walters. "They had a lot of guys graduate, a great cornerback in Talib went to the NFL. "So we'll see what happens.” There's a wait-and-see approach with many of the secondaries across the Big 12 — including the Sooners and Cowboys — where elite passing games are quick to expose deficiencies. Oklahoma boasts one of the best safeties in the country in Nic Harris. And Lendy Holmes is a fine running mate. Still, the Sooners are not only replacing both starting corners, next-in-line Dominique Franks and Brian Jackson are mostly unproven. Same with the backups, Jonathan Nelson and Jamell Fleming. Junior college transfer David Sims, considered a key component in OU's nickel package, will likely be late to camp, potentially hindering his progress. But redshirt freshman Sam Proctor was solid in the spring. The Sooners don't lack for confidence, even in a conference overflowing with talented passers. "Whatever quarterback that's on the schedule,” Harris said, "is who I like playing against.” At Oklahoma State, three starters return to what might be an underrated unit . Jacob Lacey, entering his senior season, emerged as a solid corner late last season. Perrish Cox, the other corner, is now a junior who could be on the verge of a breakout. Ricky Price made a smooth transition from receiver to free safety, starting all 13 games a year ago. OSU lost a fourth starter when Andre Sexton shifted down to the hybrid linebacker spot, but Quinton Moore has experience and juco transfer Lucien Antoine is being counted on to make an impact.