Lions safety Gerald Alexander underwent successful neck surgery last week in Los Angeles and should be able to participate in conditioning workouts when the team's offseason program begins in March, his agent Jerome Stanley said Friday.

"He's out of the brace and walking around and feels great," Stanley said. "It was very successful."

Alexander fractured a vertebrae in his neck last month trying to tackle Adrian Peterson. Stanley said he could be cleared to resume jogging and lower-body workouts next month and expects that Alexander will "do a full OTA" next spring. Even if he's cleared, the Lions, for precautionary reasons, likely will restrict Alexander until (and maybe into) training camp.