What once was a position of strength for the Kansas University football team quickly has transformed into one of the team's least experienced units.

KU coach Charlie Weis announced Tuesday night that senior running backs Brandon Bourbon (torn ACL) and Taylor Cox (torn Achilles' tendon) both will miss the 2014 season after suffering injuries during preseason camp.

“I feel bad for both Brandon and Taylor,” KU coach Charlie Weis said in a press release. “They were looking forward to the opportunity to be the replacement for James Sims. I sat down with each of them individually and talked through their options and was happy that they chose to further their education while attempting to play again next year if things work out.”

The injuries — Bourbon went down during Sunday's scrimmage and Cox at Monday's practice — bump three newcomers into pivotal roles in their first seasons as Jayhawks, as freshman Corey Avery (5-foot-10, 195 pounds) and junior-college transfer De'Andre Mann (5-9, 198) vault to the top of the depth chart and freshman Joe Dineen, a Lawrence native and Free State High graduate, moves over from safety to provide depth.

Off the Deep End Here's a look at KU's projected running back depth entering the summer and what happened to each back: • Sr. Brandon Bourbon — Torn ACL, out for season • Sr. Taylor Cox — Torn Achilles' tendon, out for season • Jr. De'Andre Mann — Competing for No. 1 spot on depth chart • Jr. Darrian Miller — Left team for personal reasons, later transferred to Northern Iowa • Fr. Corey Avery — Competing for No. 1 spot on depth chart • Fr. Traevohn Wrench — Failed to qualify academically, enrolled at Butler Community College

Tale of the Tait Check out Matt Tait's reaction to the news of injuries forcing Brandon Bourbon and Taylor Cox to miss the 2014 season. Tale of the Tait: Latest KU football injury news as unfair as it gets

“I surveyed our roster and felt Joe was the best answer to help offensive depth, while not greatly hindering the defense,” Weis said of the 6-2, 210-pound former Firebird. “He and I met after practice Monday and I gave him the choice. He was happy to move in the best interest of the team.”

The injury is the latest in a long line of medical issues that have plagued Bourbon, a 6-1, 225-pound Potosi (Missouri) High graduate who initially committed to Stanford out of high school and turned 23 years old on Tuesday.

He broke his leg during his first spring on campus and red-shirted his first season in 2010. He missed the final three games in 2011 with another leg injury and sat out the TCU and Kansas State games in 2012.

Finally healthy, Bourbon played in all 12 games last season but split time between running back (191 yards and 3 touchdowns on 41 carries) and receiver (102 yards on 20 receptions) while watching Sims lead the team in rushing for the fourth consecutive season.

As for Cox, the 5-11, 212-pound back played in all 12 games as a junior in 2012 after transferring to Kansas from College of the Siskiyous but played in just two games in 2013 and red-shirted the season after injuring his hamstring.

Although Bourbon and Cox both will be in street clothes this season, both figure to help mentor the trio of newcomers who will be asked to replace them.

“While De’Andre and Corey lack experience on the Division I level, they both have had excellent camps,” Weis said. “The team is well-aware of this situation and is excited to make the run game successful.”

Said Bourbon in an interview last week: “I enjoy De'Andre and Corey Avery, and we're just trying to get them knowing what we're doing, as well.”

That becomes even more critical now as Bourbon and Cox head to the bench, leaving running-back-turned-wide-receiver Tony Pierson as the only player on the KU roster with Div. I experience at the position.

Weis, through the depth chart or his news conferences, has said that all four guys were in the mix with the first team and that he felt great about the team's depth and talent at running back.

“It'll be, 'Let's see who the best guy is,'” said Weis on the opening day of preseason camp. “Before you even get to Corey Avery or putting Tony in the backfield a little bit, I mean, there's a lot of people that would be very happy having those guys in competition for their No. 1 running back.”

Now, it's crucial for the Jayhawks to show that their coach's faith in that depth was warranted.

In addition to rehab, next up for Bourbon and Cox is the pursuit of a sixth season of eligibility via a medical hardship waiver. Typically, college athletes are given five years to complete their four years of eligibility, however a request for a sixth season can be granted if an athlete fits the criteria.

Such criteria includes: suffering the injury during one of his or her four seasons of college eligibility; suffering a season-ending injury; suffering the injury prior to the second half of his or her season; and the athlete may not have competed in more than three games or 30 percent of his or her team's season, whichever is greater.

All aspects of the criteria must be proven with documentation. If they are, the success rate for obtaining a hardship waiver is high when athletes miss one or more seasons because of “circumstances beyond his or her control or the control of the institution,” as Bourbon and Cox's two most significant injuries have been.