When grill is heated, carefully oil grill rack. Place chicken on gas grill over medium heat or on charcoal grill over medium coals; cover grill. Cook 6 to 8 minutes, turning once, until chicken is no longer pink in center. During last 5 minutes of cooking time, heat bacon on grill, turning once, until hot. If desired, during last 3 minutes of cooking time, toast kaiser roll pieces, cut side down, on grill.