University of Wisconsin sophomore Vonte Jackson, who is attempting a comeback after suffering three torn anterior cruciate knee ligaments in less than two years, is changing positions.

In an attempt to get more speed and athleticism in the football team's secondary, Jackson is moving from running back to safety, a UW source said on Tuesday.

Jackson, from Kenosha Bradford, is the second speedy Badgers running back to make that move in the last year.

Jeff Lewis made the switch, amid high expectations, after 2013 spring practices, but he was not able to make an impact at his new position last season and moved back to running back.

Now, Jackson is making the same leap, following three major knee surgeries, two to the right knee and one to the left.

He suffered his first torn ACL in his left knee in the first game of his senior season at Bradford in August 2011. He tore the ACL in his right knee during preseason camp in August 2012 and the ACL in the right knee for a second time last June during summer workouts.

Junior Melvin Gordon and sophomore Corey Clement are expected to be UW's top two running backs next fall.

The Badgers also have oral commitments from two running backs for the 2014 recruiting class: Taiwan Deal, from Hyattsville, Md., and Caleb Kinlaw, from Goose Creek, S.C.

UW loses starting strong safety Dezmen Southward, who was a senior last season. Also, junior Tanner McEvoy, who started three games and played extensively at safety in the second half of the season, is being given a chance to compete for the starting quarterback job.

The returning safeties who played last season include junior Michael Caputo, sophomore Nate Hammon, sophomore Leo Musso and sophomore Joe Ferguson, who appeared in four games before being injured.

Early enrollment

With the start of classes on Tuesday, UW announced seven players who enrolled early, including inside linebacker Chasen Andersen, the son of UW coach Gary Andersen.

Chasen Andersen, 6-foot, 220 pounds, announced in June he was released from his letter of intent with Brigham Young and planned to walk on at UW.

As a junior at Logan (Utah) High School, he led all players in the state, regardless of classification, with 160 tackles. He missed almost his entire senior season after tearing the anterior cruciate ligament, medial collateral ligament and meniscus cartilage in his right knee in the first game of the season.

The other players to enroll early, who were not previously announced, are two walk-on linebackers from Wisconsin.

Matt Austin, 6-3, 210, is an inside linebacker from from St. Mary's Springs in Fond du Lac. He was named first-team all-state as a senior by the Associated Press and Wisconsin Football Coaches Association after posting 131 tackles, including 14 tackles for loss, with five forced fumbles and an interception. He also caught 10 passes for 228 yards and two touchdowns.

Justin Schweitzer, 6-1, 195, is an outside linebacker from Silver Lake (Wilmot). He was a two-time All-Southern Lakes Conference selection, who led his team in tackles as a junior and qualified for the state track meet in the 110-meter hurdles as a junior.

The other four players enrolled early were all previously announced.