Gophers linebacker Cody Poock has a torn anterior cruciate ligament in his right knee, a person familiar with his injury said Monday.

The team was finalizing the diagnosis, with coach Jerry Kill expected to address the injury with the media after Tuesday's practice.

Poock suffered the injury at Saturday's practice. On Sunday, he posted on his Twitter page (@codyallenpoock), "Everything happens for a reason."

It's a tough blow for the Gophers, as Poock had been playing with the first-team defense, alongside linebackers Damien Wilson and De'Vondre Campbell.

Poock is expected to have surgery soon, and his ability to return this fall will depend on how he heals. Last year, Michigan linebacker Jake Ryan suffered a torn ACL injury in spring practice. He had surgery March 28 and was back playing again for the Wolverines on Oct. 12.

Gophers cornerback Briean Boddy-Calhoun tore an ACL in the season's second game last year (Sept. 7 at New Mexico State), and he already has seen time in 11-on-11 drills this spring.

Poock still has three years of eligibility remaining after transferring from Iowa Western Community College. He had the grades to play Division I coming out of Spirit Lake High School last year but didn't get the offers he wanted, so he went the junior college route.

He made 80 tackles for an 11-1 Iowa Western team and picked Minnesota over TCU. This spring, he quickly emerged as the leading candidate to replace departing senior Aaron Hill at strongside linebacker.

Nick Rallis, a redshirt sophomore from Edina, filled in for Poock with the first-team defense for the rest of Saturday's practice. The Gophers have been pleased with Ray Dixon's play with the second-team defense, making him another candidate to replace Poock.

With Wilson entrenched at middle linebacker for one more year, it's also possible the Gophers could move his backup, Jack Lynn, to an outside spot this fall.

Gophers add defensive back

The Gophers made a late addition to this year's recruiting class Monday, when Ra'Shaun Croney, a defensive back from Pahokee, Fla., signed his national letter of intent.

Croney, a consensus three-star recruit, had offers from Arkansas and South Carolina but wound up committing to Ellsworth (Iowa) Community College, when it looked as if he might not qualify academically for Division I.

Croney's grades have been on the rise, so the Gophers invited him for an official visit last weekend. They were looking for another defensive back in this class to join Craig James, from Edwardsville, Ill., after missing out on a few others, including Khari Blasingame, who flipped his commitment to Vanderbilt.

It's a key signing for the Gophers because four of their defensive backs — Derrick Wells, Cedric Thompson, Marcus Jones and Grayson Levine — will be seniors this fall.