The Facts: Ebron's quest to play a full 16-game season for the first time in his NFL career is off to a rough start. Ebron left the first practice of training camp Sunday with what HC Jim Caldwell said appeared to be a hamstring injury. "He got a little bit of a tweak but we'll see, see how bad it is," Caldwell said.

Diehards Line: Ebron did not take part in any team drills, leaving Darren Fells and Cole Wick to take reps with the first-team offense. While Caldwell did not sound any alarms about it being a possible long-term ailment, given Ebron's injury history and the extent of the pain he played through last year, the Lions can't afford to have their No. 1 tight end dealing with injuries this fall. Ebron set career-highs with 61 catches for 711 yards last season and is expected to play an even bigger role on offense this fall. ... Also worth noting: RB Theo Riddick worked in a red no-contact jersey as he makes his way back from double-wrist surgery.