The Cowboys placed Bullard (calf) on injured reserve Wednesday, Tommy Yarrish of the Cowboys' official site reports.
Bullard suffered a calf injury during the Cowboys' Week 3 loss to the Ravens. The injury is severe enough for him to require a stint on IR, which means he'll have to miss at least the next four games and is eligible to return for Week 8 against the Cardinals on Sunday, Nov. 1. Rookie fourth-rounder LT Overton could see a bump in rotational defensive snaps for as long as Bullard is on the shelf.