Raiders promote ball security after fumbles against Chiefs

Early in Wednesday’s practice, Raiders running backs went through a drill where they carried a ball while coach Jemal Singleton jabbed at them with a boxing glove on a stick. Thursday, the running backs dropped to the ground and popped back up while holding a ball on a string with Singleton tugging at the other end.

Raiders running backs committed three costly fumbles in last Sunday’s 40-33 loss to the Chiefs, making ball security an even stronger point of emphasis this week.

“If you’re a ball-carrier ... and you’ve shown you’ll put the ball on the ground, you become a target for sure,” offensive coordinator Greg Olson said Thursday. “So we’ve got to clean that up.