ALLEN PARK -- The Detroit Lions' fears have come to pass.

Rookie linebacker Kyle Van Noy, once considered the favorite to start at strong-side linebacker, will miss the first eight weeks of the season.

The Lions announced Tuesday they've moved their second-round pick to short-term injured reserve while he recovers from surgery to repair a core muscle injury.

That designation allows the Lions to add another player to the 53-man roster, and they re-signed defensive end Darryl Tapp accordingly. But the designation also means Van Noy must miss the first half of the season.

Detroit is off in Week 9, which means Van Noy will be eligible to return Nov. 9 against the Miami Dolphins.

He can return to practice in six weeks.

Detroit now turns to Tahir Whitehead at strong-side linebacker. Whitehead has spent the entirety of his two-year career as a special teams ace, but rose into the defensive rotation during the preseason and is listed as the starter for Monday's opener against the New York Giants.

With Van Noy out, Whitehead's backup will be Ashlee Palmer, who started at the position last year.

Tapp was with the team throughout the offseason. He once was considered a strong candidate to make the team, but was outplayed by defensive end George Johnson and among the final cuts Saturday.

Tapp has experience playing linebacker in a 3-4, so he could be a depth guy at defensive line and linebacker. He also contributes on special teams.