The knee injury suffered by University of Wisconsin defensive lineman Dan Moore is not as severe as initially feared, but Moore's status won't be known until he undergoes further tests.

UW football coach Bret Bielema said on Tuesday the options for Moore, who was injured in practice on Saturday, range from "major surgery, or minor surgery, or maybe no surgery at all."

"It really depends on what they find out later (Tuesday)," Bielema said.

Moore, a junior college transfer who had impressed the coaches as the backup at right defensive end to Matt Shaughnessy, will be out the remainder of the spring.

Moore suffered the injury while going against center Brad Thorson during the "Badger" drill, in which one offensive player and one defensive player line up against each other in three-point stances, then fire out at the whistle and make contact with each other.

Bielema also announced that Thorson, a sophomore backup, has left the program.

"Brad is going to explore other options," Bielema said. "I had a discussion with him (Monday). We'll do whatever we can, to give him support ... through the rest of the semester."

Bielema was vague when asked if Thorson's departure had anything to do with the circumstances regarding Moore's injury.

"There's a lot of things that go into the situation that brought Brad to where he is," Bielema said. "From a head coaching standpoint, the only thing I care about is the well-being of our players."

Thorson, from Mequon Homestead, originally committed to Minnesota before changing his mind and signing with the Badgers.

Bielema has a policy that he will not release a player to transfer to any team that is on the Badgers' schedule for the length of that players' remaining eligibility.

"Brad has three years of eligibility remaining, so those would be the three years of schools (on UW's schedule) he wouldn't be allowed to talk to, that I would deny," Bielema said.

The injury to Moore is another blow to a UW defensive line that has been devastated by injuries this spring. Moore was one of seven defensive linemen who sat out practice with injuries.

Three of those players are starters who are out for the remainder of the spring: sophomore end Kirk DeCremer (back), senior tackle Jason Chapman (knee) and senior tackle Mike Newkirk (shoulder).

The other injured players are sophomore end Ricky Garner (hamstring), junior tackle Dan Cascone (shoulder) and sophomore tackle Brandon Hoey (back). Garner's injury is more severe than initially thought, although he could be back by next week.

"Ricky had a pretty significant hamstring (pull)," Bielema said.

Without Garner and Moore, redshirt freshman Evan Millard, a walk-on linebacker from Palm Beach Gardens, Fla., worked with the No. 2 defense at right end.

Bielema said he could not recall another spring with so many injuries. Among the projected defensive starters who are out, in addition to the three linemen, are cornerbacks Aaron Henry and Allen Langford, who are coming off ACL surgeries; and senior linebackers DeAndre Levy (back) and Jonathan Casillas (ankle).

Levy missed Tuesday's workout after his back tightened following a good showing in the scrimmage on Saturday.

"He scrimmaged probably as well as I've seen him play," Bielema said. "Sunday when he got up, was real tight in the back. (Monday), once he started to lift, really aggravated it, had some spasms. He's a lot better (Tuesday)."

Bielema said he expects Levy to practice on Thursday. Casillas, who suffered an ankle injury last Thursday, could be out for the remainder of the spring.

Middle linebacker Elijah Hodge, who had been out after minor knee surgery, took part in his first full practice and worked with the No. 2 defense.

The injuries have not been as severe on offense, although the Badgers have been without tight ends Travis Beckum and Garrett Graham, who are recovering from shoulder surgeries. They have been cleared to run routes but are not expected to practice this spring.

"In December, when we were scheduling all the surgeries, I started counting the numbers and understanding exactly who was going to be missing," Bielema said. "From a defensive point of view, we had potentially eight starters out on defense alone.

"Garrett and Travis are pretty big impact players for us offensively. Not to have them out there ... but on the flip side of it, it's the first time we've had (tailback) P.J. (Hill) through all winter conditioning and I thought he's really made a gigantic step as a football player."