OU football: Breaking down Oklahoma's defensive personnel 

Oklahoma linebacker Kenneth Murray warms up during practice on April 1 at Owen Field. (Kyle Phillips / The Transcript)

NORMAN — Sorting through defensive depth won’t be easy when Oklahoma football begins practice Saturday.

With a new players, some subtractions and a new system under defensive coordinator Alex Grinch there figures to be plenty of fluidity to the Sooners’ lineup. It’s a difficult group to project before fall camp.

Here’s a roster breakdown on the defensive side of the ball, with a look at who could start, which position battles are most enticing and who’s available.

Inside linebackers

• The frontrunners: Kenneth Murray (6-2, 212 Jr.), DaShaun White (6-0, 224 So.)

• The competition: Bryan Mead (6-2, 229 R-Jr.), Levi Draper (6-1, 245 R-So.), Ryan Jones (6-2, 236 R-So.).

• Others of note: Brian Asamoah (6-1, 225 R-Fr.)

• Rating the position battle: It’s an 8/10, mainly because any job in the new defense will be entertaining to monitor. Two jobs seem spoken for: Murray is a fixture at middle linebacker (Mike), while White’s experience a year ago makes him a likely starter at the weakside spot (Will). But guys like Draper and Mead will push for playing time. OU’s players are expected to know the Mike and Will spots, so there could be movement.

• Why it matters: Caleb Kelly’s injury will likely mean a redshirt year for him, and it increases the importance of improved depth. Don’t be shocked if an outside linebacker — a Nik Bonitto (R-Fr.) or Jon-Michael Terry (R-Jr.) — needs to move inside at some point.

Jack linebacker

• The frontrunners: Ronnie Perkins (6-4, 273 So.); Jalen Redmond (6-3, 264 R-Fr.)

• The competition: Mark Jackson (6-1, 238 Sr.)

• Others of note: Joseph Weté (6-4, 211 Fr.)

• Rating the position battle: 7/10. Perkins made a number of starts here once the defense transitioned following Mike Stoops’ departure, while Jackson faded into the background. Coaches are also excited about Redmond’s potential; but Redmond and Perkins could also both play defensive end.

• Why it matters: OU’s lowly pass coverage isn’t all on the secondary, as the Sooners really struggled getting pressure on the quarterback last season. They weren’t a force up front in 2017 by any means, but Ogbonnia Okoronkwo was still a difference-making player. OU’s at least trying to find someone similar.

Defensive tackle

• The frontrunner: Neville Gallimore (6-2, 301 R-Sr.)

• The competition: Dillon Faamatau (6-3, 290 R-Sr.), Marquise Overton (6-1, 304 R-Sr.)

• Others of note: Troy James (6-1, 286 R-So.), Jordan Kelley (6-3, 294 R-Fr.)

• Rating the position battle: 4/10. The nose guard spot is Gallimore’s, with Faamatau and Overton giving him breathers. It’s a rare group in that they’re all fifth-year seniors.

• Why it matters: It’s a big year for Gallimore. He can increase his NFL Draft stock by becoming a disruptive figure behind the line of scrimmage, both while giving the defense a huge boost.

Defensive end

• The frontrunners: Kenneth Mann (6-3, 269 R-Sr.); Ronnie Perkins (6-3, 248 So.)

• The competition: LaRon Stokes (6-4, 267 Jr.), Isaiah Thomas (6-5, 256 R-So.), Kori Roberson (6-4, 273 Fr.)

• Others of note: Marcus Stripling (6-3, 257 Fr.), Marcus Hicks (6-5, 268 Fr.)

• Rating the position battle: 8/10. While Mann and Perkins/Redmond are pretty good bets to start, watch how the other names develop. Coaches have been impressed by Stokes, who enrolled in December after emerging as a junior college prospect out of Northeastern Oklahoma A&M. Stripling and Hicks were both four-star products out of high school.

• Why it matters: See above. For any defensive line, especially OU’s, it’s all about more disruption.

Cornerback

• The frontrunners: Tre Brown (5-10, 185 Jr.), Parnell Motley (6-0, 178 Sr.)

• The competition: Tre Norwood (6-0, 184 Jr.), Miguel Edwards (5-11, 171 R-Jr.),

• Others of note: Starrland Baldwin (5-11, 161 R-Fr.)

• Rating the position battle: 8/10. Grinch was not sold on anyone in the spring and unwilling to hint at starters. Conceivably Brown and Motley have the inside track considering their many starts together, and also since it seems Norwood is likely to stay at nickelback or safety and the other options are younger players. But an underclassman could step up and swipe the job with a big performance in camp.

• Why it matters: OU ranked 129th nationally against the pass last season.

Nickelback

• The frontrunner: Brendan Radley-Hiles (5-9, 180 So.)

• The competition: Justin Broiles (5-10, 189 R-So.), Tre Norwood (6-0, 184 Jr.), Caleb Murphy (5-11, 206 R-Fr.)

• Others of note: Ty DeArman (5-11, 191 Fr.), Woodi Washington (5-11, 182 Fr.), Jamal Morris (6-2, 192 Fr.)

• Rating the position battle: 6/10. Even with his struggles last year, Radley-Hiles should be able to assert himself here after 11 starts. Others who’ve been mentioned are Murphy and Morris.

• Why it matters: Opponents, like West Virginia and WR David Sills especially, picked on OU’s weakness here a year ago. Finding strength at this position is a big focal point for Grinch.

Safety

• The frontrunners: Patrick Fields (5-11, 196 So.), Delarrin Turner-Yell (5-10, 193 So.)

• The competition: Robert Barnes (6-2, 207 Jr.), Tre Norwood

• Others of note: Jeremiah Criddell (5-11, 198 Fr.) Jordan Parker (5-11, 181 R-Fr.)

• Rating the position battle: 10/10. This is the Sooners’ thinnest position — to the point where two sophomores were mentioned as the leaders to start in the spring — and one of its more flexible. Radley-Hiles and Norwood and can both play safety or nickel. Criddell was a huge four-star pickup for the Sooners on signing day.

• Why it matters: If underclassmen rein supreme atop the depth chart, it could signal that Grinch is going all in on guys like Criddell, Fields and Turner-Yell in hopes of a better future.

OU football dates to know

Friday: Local media day / “Meet the Sooners”

Friday: Players report

Saturday: First practice

Aug. 5: Partial practice open to media

Aug. 13: Partial practice open to media

Sept. 1: Season opener vs. Houston