During three mostly forgettable years with the Arizona Wildcats, Chris Merrill played in 19 games and registered exactly 10 tackles.

He was a space-filler, often because his position - defensive tackle - demanded he do just that.

Merrill has since been promoted.

The fifth-year senior was listed as starting rush end in the UA's first depth chart of the season, released Monday. He's expected to play significant snaps Saturday, when the Wildcats take on Toledo at Arizona Stadium.

It's quite the role reversal for Merrill, who has just one career start and guesses he has played "maybe 50" regular-season snaps.

"It's been a long journey," he said. "I just try to come every day, try to work hard and do everything in my power (to improve). If I mess up or whatever, I try to put it behind me and bust my (butt) and try to do what I can to improve."

Here's everything you need to know about Merrill:

The basics: Merrill stands 6 feet 2 inches tall, weighs 273 pounds and prepped at Scottsdale's Saguaro High School.

Known for: His work ethic. Merrill's raw numbers and career statistics don't show exactly how well-respected he is in the locker room. Coaches love the way Merrill grinds; it's one of the reasons his stock rose during a long, hot August. His adaptability - Merrill can play all three line spots in the Wildcats' new 3-3-5 "odd stack" defense - only adds to his value.

First-year coach Rich Rodriguez calls Merrill "a great young man."

"He's a 'program guy' that's got great strength, plays hard, and I think he can play multiple positions up front on our D-line," Rodriguez said.

Merrill's position coach, Bill Kirelawich, was more direct.

"He hustles," Kirelawich said. "He tries like hell."

Before Arizona: Merrill was listed as the state of Arizona's 19th-best prospect as a high school senior. He chose the UA over offers from Arizona State and Portland State.

Merrill said this week that his commitment meant something; he never seriously considered transferring, even as playing time and coaching turnover provided distractions.

"I've been determined to finish this thing out," he said. "I was committed to this school, and I'm still committed to this school. I want to finish it out here."

Early college career: A two-way player in high school, Merrill switched exclusively to defense after arriving at the UA in 2008. Playing time and success proved hard to come by: He redshirted as a true freshman, then managed just two total tackles in 2009 and 2010 combined. It didn't help that Merrill was backing up veteran defensive tackle Lolomana Mikaele and a newcomer, Justin Washington, who might have been the team's most surprising player in 2010.

A strong finish: Merrill was moved to defensive end at the start of the 2011 season and played a bit more. It took Mike Stoops' dismissal and the promotion of linebackers coach Tim Kish for Merrill to see more of the field: He registered three tackles in the Wildcats' loss to Colorado in mid-November, and was rewarded with a start - the first and so far only of his career - against Louisiana-Lafayette.

Though he played more than ever, Merrill calls the 2011 season the low point of his career.

"We put so much into it," he said, "and didn't get much out of it."

A close connection: Merrill counts another fifth-year senior, Matt Scott, among his best friends on the team. The two lived together earlier in their careers - "an offensive guy and a defensive guy, actually getting along," Merrill said - and have been sounding boards for each other during tough times.

It's fitting, then, that both seem to be finally getting opportunities to start in their fifth and final season.

"Me and Matt have both just continued to work and continued to put our noses to the grindstone," Merrill said. "When we got our opportunities, we worked hard and took advantage of them."

Fresh start: Merrill, like the rest of the Wildcats' defense, will be a work in progress in 2012. Coaches are trying to temper their expectations for a group that's coming off the worst statistical season in program history, and figures to be just as bad - if not worse - this fall.

Still, Merrill said he's excited to start a new chapter as something other than a space-filler.

"We're just excited to put the past behind us and take on what we have now," Merrill said. "We've been working harder than we ever have; let's just take control of what we've got, and go for it."

The Rodriguez report

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

Injury report

• Out: OL Addison Bachman (concussion), LB Dakota Conwell (foot), LB Rob Hankins (concussion), LB Greg Nwoko (hip), DE Dan Pettinato (knee), TE Drew Robinson (concussion), OL Trent Spurgeon (ankle)

• Questionable: LB Hank Hobson (shoulder)

• Doubtful: None

• Probable: None

Team captains

• Week 1 vs. Toledo: QB Matt Scott, C Kyle Quinn, DL Dominique Austin and P Kyle Dugandzic

Up next

• What: Toledo at Arizona

• When: 7:30 p.m. Saturday

• TV; radio: ESPNU; 1290-AM, 107.5-FM, 990-AM (Sp)