Chargers coach Jim Harbaugh leads his players onto the field before Saturday’s preseason game against the Rams.

(Allen J. Schaben / Los Angeles Times)

How many ways can a team sabotage itself? The Chargers tried to answer that question in the first half.

Costly errors and turnovers turned promising drives into setbacks. Stick’s goal-line fumble in the second quarter came after a 13-play, 49-yard drive.

“It’s on me,” Stick said about the fumble. “It was a good snap. It hit my hands, and I dropped it.”

The following series, the Chargers squandered a promising drive, highlighted by a 22-yard catch and run by Simi Fehoko. Under pressure from the left side, Stick threw an errant pass intended for Fehoko, which was intercepted by Rams cornerback Jaylen McCollough.

On their next possession, the Chargers moved into scoring position again when Stick connected with Fehoko on a 30-yard pass to the Rams’ 24. But after three carries by running back Elijah Dotson, the drive was derailed by a false start on offensive tackle Foster Sarell, forcing the Chargers to settle for a 37-yard field goal.

“Those are the things you can’t do,” Harbaugh said. “We have to focus on the details and control the things we can control in all phases — offense, defense and special teams.”