When Tra'Mayne Bondurant cracked the Arizona Wildcats' starting lineup in 2011, he was a rarity: a true freshman who worked hard and caught a break.

If he only knew.

A coaching change, injuries and departures have meant even more opportunities for underclassmen in 2012. Bondurant is, by comparison, a grizzled veteran.

Arizona has played 40 freshmen and sophomores so far this season, more than half of 75 Wildcats who have seen the field. Ten of the 40 are true freshmen, the fourth-highest total among Pac-12 schools.

Things are especially thin on defense, where 14 of 22 players listed on the "two-deep" - and six of the team's top eight tacklers - are either freshmen or sophomores.

"We are playing everybody, every healthy body we've got defensively and offensively - and some are probably playing before their time," first-year coach Rich Rodriguez said.

"I've never been in a position like we've been in, as thin as we were to start the season, let alone where we are right now. We were razor thin defensively, then we were past thin, now we're past that."

Things won't get easier anytime soon. Arizona (5-4 overall, 2-4 Pac-12) will take on Colorado this weekend without a handful of its projected starters. Arizona's injury report, released Thursday, was eight players long. Quarterback Matt Scott, guard Chris Putton and safety Jourdon Grandon were listed as doubtful to play because of concussions; linebacker Hank Hobson is out because of a nerve issue in his neck.

The injured players will be replaced by a group of excitable, if not experienced, underclassmen. Like these guys:

The top sophs

1. RB Ka'Deem Carey: Sophomore leads the Wildcats with 1,015 rushing yards and has scored 13 touchdowns. The former Canyon del Oro High School star also has 28 catches, third-most on the team, for 247 yards.

2. WR Austin Hill: Has caught a team-best 59 passes for 994 yards and seven scores. No other UA player has more than 54 grabs or 678 receiving yards.

3. S Tra'Mayne Bondurant: "Bandit" safety leads the UA with 11 1/2 tackles-for-loss and is fourth on the team with 57 total stops.

Just missed the cut: OT Mickey Baucus, OT Fabbians Ebbele, DB Jonathan McKnight

True freshmen making a difference

1. S Wayne Capers Jr.: Do-it-all freshman plays on all special teams and has been seeing limited playing time on defense.

"I thought I was going to get redshirted," said Capers, who has three tackles this season. "When they told me I wasn't going to get redshirted, I thought, OK, I'd be playing special teams. Looks like I've been helping on defense, too."

2. OL Cayman Bundage: Big (6 feet 2 inches, 265 pounds) and tough, the soft-talking Oklahoman has carved out a role in the Wildcats' injury-riddled offensive line. Bundage is expected to start with Putton hurt.

3. S Will Parks: Philadelphia native has six tackles this season, most by any true freshman. Coaches and teammates love the way Parks hits; he's a regular on special teams.

Just missed the cut: LB C.J. Dozier, LB Dakota Conwell, DE/LB Keoni Bush-Loo

Three unlikely contributors

1. S Vince Miles: Walk-on has been a special teams standout and fill-in player so far this season. He recovered a fumble in the second half of Arizona's game against USC two weeks ago; the Wildcats rallied to win 39-36. With Grandon likely out, Miles could make his first career start.

"I definitely didn't think my opportunity would come this early," he said. "We've got a lot of young guys playing, and for the most part, they're going out there and doing what we need them to do."

2. S Jared Tevis: Former walk-on has been one of the Wildcats' most productive defensive players this season. The safety ranks fifth on the team with 49 tackles, even though he missed nearly three of the team's nine games with an ankle injury.

3. WR Johnny Jackson. A high school running back turned college wide receiver, Jackson - a walk-on - is making the most of his opportunity to play. He caught nine passes in a quarter against Stanford before being knocked out with an injury and caught his first career touchdown pass against USC.

Just missed the cut: DT Tevin Hood, LB Sir Thomas Jackson, DE Justin Washington

Redshirting - and waiting

1. DE Kyle Kelley: The top recruit in Arizona's 2012 class, Kelley has opted to redshirt with an eye on contributing - if not starting - between 2013 and 2016.

2. WR Trey Griffey: The only football player among baseball royalty - his father is Ken Griffey Jr., and grandpa is Ken Griffey Sr. - Trey has been showing promise at wide receiver. Arizona's depth at the outside receiver spots means Griffey can afford to redshirt this year.

3. RB J.T. Washington: Speedy Floridian has done a good job of mimicking opposing running backs in practices. Few players are faster, or shiftier.

Said Miles: "He gives us a good scout look every week."

The Rodriguez Report

UA coach Rich Rodriguez's injury report and team captains for this week's game against Colorado:

Injury report

• Out: LB Hank Hobson (neck), DE Dominique Austin (foot, season-ending), WR Terrence Miller (ankle).

• Doubtful: QB Matt Scott (concussion), S Jourdon Grandon (concussion), OG Chris Putton (concussion)

• Questionable: FB/DE Taimi Tutogi (neck)

• Probable: DE Kirifi Taula (shoulder)

Team captains

C Kyle Quinn, DL Lamar De Rego, RB Elliot Taylor, LB Jake Fischer


• Who: Colorado (1-8, 1-5) at Arizona (5-4, 2-4)

• When: 11:30 a.m. Saturday

• TV: FX

• Radio: 1290-AM, 107.5-FM, 990-AM (Spanish)

On StarNet: Read the transcript of Ryan Finleys's chat from Thursday at live.azstarnet.com