Lose ball, lose job? 49ers RBs focused on ball security

On Saturday, the 49ers running back appeared poised to finish off a 12-yard scoring run … before he fumbled at the one-yard line when smacked by two Denver defenders.

Harris fell into the end zone and loose ball fell in the hands of cornerback John Tidwell.

The 49ers have lost five fumbles in two preseason games and their running backs have been the primary culprits.

Mike Davis lost two fumbles Saturday, Carlos Hyde had a fumble returned for a touchdown in the preseason opener and Harris was involved in a botched handoff on 1st-and-goal at the 2 in the first exhibition game.

“I think (running backs coach) Tom Rathman does a tremendous job with our backs, but a little responsibility goes to them,” Kelly said.

Another fumble could be dire for Harris or Davis, who might be fighting for a roster spot if the 49ers only keep one other running back after Hyde and Shaun Draughn.

Offensive coordinator Curtis Modkins, 45, an all-conference running back at TCU, was asked this week about any helpful ball-security tips he received during his playing days.

Modkins recalled he once lost two fumbles against Arkansas, turnovers that keyed the Razorbacks’ come-from-behind win.