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

• Rookie running back Kevin Smith took the first three snaps in most team periods Sunday morning and appears to have passed Tatum Bell for the No. 1 job. Lions coach Rod Marinelli wouldn't say as much after practice, but Smith and rookie fullback Jerome Felton could be your starters next week against Cincinnati. "We're just rotating guys in," Marinelli said. Pressed on the issue, Marinelli said angrily, "If you want to read something into it, read it. That's on you."

• Bell declined to talk after practice, as he has much of the preseason, and Smith said, "Don't know" when asked about any depth chart changes. "I don't get caught up in that," he said.

• It should be noted that Smith took first-team reps Saturday, too, but most of the media was in the press room when practice started — Marinelli was available before the workout — and weren't ushered onto the field until after practice ended.

• Jon Bradley, who had been No. 1 at fullback, sat Sunday with what Marinelli termed a bothersome shoulder. Receiver Calvin Johnson also sat out Sunday's practice with a leg bruise. Johnson dressed for practice, while Bradley did not. "It's just a bruise so I was just being on it," Marinelli said of Johnson, who was hampered last year by a bad back.

• Offensive coordinator Jim Colletto has decided he will call plays from the coaches box this year. Colletto said last week he was going to alternate between the field and box this preseason to determine where he'd spend his gamedays. He spent Thursday's win over the Giants on the field and said "that experiment ended real fast." "I thought I'd try it, get on TV one time, that's it," Colletto said. "It's a zoo down there. It's too hard to think and they don't need me ragging on them, the coaches don't need me ragging on them. I'm going up there."

• Rookies Gosder Cherilus and Jordon Dizon have a chance to join Smith and Felton in the starting lineup, but for now they remain second- and third-string, respectively. Marinelli praised Cherilus for his performance at right tackle against the Giants, despite drawing three penalties. "Gos played pretty well," he said. "He knocked some people off the ball now." Dizon still isn't locked in on defense, but he's a playmaker. In Sunday's morning practice, which was without pads because the Lions are down on healthy bodies, Dizon deflected two passes over the middle with two good reads.