Every day during training camp, Lions beat writer Dave Birkett takes you inside practice at Allen Park with notes, quotes and observations of interest.

• Now that linebacker Takeo Spikes has officially spurned the Lions — he signed with San Francisco late Sunday— it's time for the Lions to figure out which middle linebacker will change positions. The way I see it, there's two choices. Either Paris Lenon moves from starting middle linebacker to starting on the strong side, or Jordon Dizon moves from Lenon's backup to the SAM position, where he'd eventually start as well. In my opinion, Buster Davis is a backup middle linebacker, either to Lenon or Dizon.

• For the 100th time this camp, defensive coordinator Joe Barry said Monday a change of position has not even been approached yet, though he acknowledged it could happen. "We'll keep however many linebackers we keep, six or seven," Barry said. "Those will be the best six or seven linebackers. And the three guys that start will be the three best linebackers that we have on this team." Dizon, the rookie second-round pick, isn't in the top three yet, but he will be by the end of the year. He needs to be on the field. Barry said he wouldn't expect a player to change positions and be ready to start a week later at their new spot. In other words, if Dizon stays in the middle until cut day Aug. 30, it's unlikely he'll start on the strong side in the season opener Sept. 7. "We've still got three preseason games left to play," Barry said. "There's not been any talk of moving anybody, middle linebackers included, to another position."

• Dizon put a great spin move on Sean McHugh in a one-on-one blocking drill today. In the drill, a running back stands seven yards from an oncoming linebacker and tries to prevent him from reaching a nearby tackling dummy. Kevin Smith fared well in protection, winning battles with Lenon and Leon Joe but getting steamrolled by Ernie Sims.

• Sims, by the way, is virtually unstoppable in the drill. He practices with such violence and intensity it's fun to see.

• Coaches aren't standing for any penalties in camp after having six in the preseason opener. Michael Gaines false-started on one play and was immediately replace. Same with John Owens a few plays later.

• Fullback Jon Bradley and receiver Taye Biddle were held out of practice Monday for injury reasons. Owens, Cory Redding and Calvin Johnson were back after resting minor ailments, and safety Daniel Bullocks, tight end Dan Campbell and receiver Shaun McDonald came off the physically unable to perform list. Campbell will be a welcome addition to both the passing and running games this year.