Michigan State has consistently had one of the better defenses in college football under Mark Dantonio and coordinator Pat Narduzzi, but the Spartans might enter the 2014 season without a key piece on that side of the ball.
Dantonio told reporters after the team's first preseason practice that Damon Knox suffered an injury and appears to be headed under the knife.
"Damon Knox right now has got some surgery, so he'll be out for a little bit of time," said Dantonio on Saturday, according to MLive.com. "But it is what it is, so we've got to deal with that. So we'll have to see about injuries."
The tight-lipped head coach did not provide any further details as to what the injury is, if Knox had already had surgery yet or what kind of playing time he would miss.
The Spartans open the season on August 29 against an FCS opponent at home but travel to Eugene in Week 2 for a huge non-conference matchup against Oregon.
Knox was slated to replace Tyler Hoover (now with the Indianapolis Colts) at defensive tackle and appeared to solidify himself as the starter coming out of spring practices. Senior James Kittredge figures to see an increase in playing time with Knox's absence, but MLive.com notes junior Lawrence Thomas could be an option, as well.
Even though the team will be missing a big interior presence for an undetermined amount of time, the Spartans should be just fine with defensive end Shilique Calhoun coming off the edge as one of the best defensive players in the Big Ten.
The 6-foot-5, 280-pound Knox had 22 tackles in a reserve role on Michigan State's Rose Bowl-winning team last season.
Michigan State is ranked seventh in the country in College Football 24/7's team rankings. The Spartans return a number of key starters from last year's 13-1 campaign and should be one of the favorites in the Big Ten East Division along with Ohio State.
You can follow Bryan Fischer on Twitter at @BryanDFischer.