A challenge for every college football team in the offseason is the task of replacing starting seniors who are often leaders of the team.

For the ISU football team, the unit that will be hardest hit with replacement needs is the defense, which saw the departure of six starting seniors with the end of the season.

Overall, there are 10 positions that will have new starters once the Cyclones’ season opener against Tulsa on Sept. 1 rolls around. Here is a breakdown of each position and the projected players to fill those vacancies.

Left tackle — 72 Kelechi Osemele

Standing at 6-foot-6, 347 pounds, Osemele was larger than life at the left tackle position for the Cyclones. Osemele, who was named a 2011 first-team All-American by Sports Illustrated, started a team-high 44 consecutive games in his time as a Cyclone.

Likely replacement: Carter Bykowski

Bykowski, a redshirt senior, split reps with Kyle Lichtenberg when not solely taking over for Osemele while he was nursing injuries.

Right guard — 75 Hayworth Hicks

Along with Osemele, Hicks was another staple on the offensive line. The 6-foot-3, 336-pound native of Palmdale, Calif., started a total of 24 games as a Cyclone and has a chance at getting his name called come draft day.

Likely replacement: Jacob Gannon

The Iowa City native is likely next in line at right guard barring a significant overhaul of personnel.

Wide receiver — 6 Darius Darks, 7 Darius Reynolds

The Darius tandem has been a staple near the sidelines on Saturdays. Reynolds had a breakout season in 2011, leading the team in catches (43), receiving yards (695) and touchdowns (seven). Darks accumulated 1,346 receiving yards in his four years as a starter, hauling in 127 passes and seven career touchdowns.

Likely replacements: Aaron Horne and Albert Gary

It is difficult to pinpoint exactly who will be starting at receiver since different personnel groups often fluctuate. Based on the depth chart, however, Horne and Gary are next in line for Darks and Reynolds’ spots.

Left defensive end — 48 Jacob Lattimer

Lattimer’s trademarked long locks of hair were emulated by his self-described “balls out” style of play on the field. In three seasons at Iowa State, Lattimer accumulated 85 total tackles, seven sacks and two forced fumbles while leading the team in sacks with four in 2010.

Likely replacement: Willie Scott or David Irving

Looking at the depth chart, Willie Scott is next in line. Size-wise, however, Irving’s 6-foot-7, 261-pound build could prove more durable than Scott’s 6-foot-2, 223-pound frame.

Nose tackle — 97 Stephen Ruempolhamer

Known affectionately as “Dutch” (having been born in Holland), Ruempolhamer was the durable man in the middle for the Cyclones. His career stat line reads with 91 total tackles, six sacks and two forced fumbles.

Likely replacement: Walter Woods III

Woods outweighs Ruempolhamer by five pounds on the depth chart — weighing in officially at 303 pounds — and is likely to be a solid gap-filler come September.

Right defensive end — 91 Patrick Neal

Neal played fullback and tight end before finding himself as a starter on the defensive line in 2009. The West Des Moines native led the team in sacks in 2011 with 3.5, also tallying a career total of 98 tackles as a Cyclone.

Likely replacement: Roosevelt Maggitt

Maggitt had originally held the starting job at the position until sustaining a season-ending knee injury in the second quarter of the season-opening 20-19 win against Northern Iowa on Sept. 3.

Mike linebacker — 45 Matt Tau’fo’ou

Tau’fo’ou encountered a spell of misfortune in his first season as a starter, breaking his leg in the Cyclones’ 35-7 loss to Iowa in 2010. He bounced back in 2011, recording 72 total tackles — good for fourth most on the team.

Likely replacement: Jevohn Miller

Sporting a frame similar to that of Jake Knott’s — 6-foot-4, 244 pounds — the true sophomore will likely switch from will linebacker to mike to take Tau’fo’ou’s place.

Right cornerback — 23 Leonard Johnson

Accompanying Osemele in Indianapolis at the NFL combine will be Leonard Johnson, who started 43 career games as a Cyclone. Johnson was instrumental in Iowa State’s monumental victory against No. 2 Oklahoma State in 2011, intercepting a pass in the fourth quarter as the Cowboys were driving with a seven-point lead.

For his career, Johnson recorded 247 total tackles, six interceptions — at least one in all four seasons — and six forced fumbles.

Likely replacement: Jansen Watson

Watson expressed interest to the media about being Johnson’s replacement last season and will likely assume that spot come September.

Strong safety — 22 Ter’Ran Benton

Once referred to as a “true nickel [back]” by defensive coordinator Wally Burnham, Benton fit in nicely at strong safety with a career-high 66 tackles in 2011. Benton led the team in interceptions last season with three, including a big one that prevented the Cowboys from scoring in overtime of Iowa State’s victory against No. 2 Oklahoma State.

Likely replacement: Jared Brackens

Assuming no major position changes take place in the secondary, Brackens should be next in line to start at strong safety.