PITTSBURGH — Los Angeles Chargers quarterback Justin Herbert suffered a serious right ankle injury during Sunday’s 20-10 loss to the Pittsburgh Steelers and left the stadium in walking boots.

Herbert was sacked by outside linebacker Elandon Roberts and got up with a noticeable limp. Herbert handed the ball off to running back JK Dobbins on the next play, but then limped to the sideline and had his ankle examined by trainers.

“Yeah, my responsibility as a quarterback is to do everything I can for this team and my teammates, and I felt like I did that,” Herbert said. “I was pushing myself and I couldn’t keep going. I had a hard time walking on it, moving on it and pushing off of it, and I knew Taylor (Heinicke) gave us a better chance to win.”

Herbert suffered a high ankle sprain in the Chargers’ win over the Panthers last Sunday and practiced only once before the game against the Steelers. He said his ankle was “sore” throughout the game, but the pain became more severe after the sack.

Chargers coach Jim Harbaugh said he considered not letting Herbert play at all on Sunday, but was pleased with Herbert’s progress after watching him practice on Saturday.

“I’ve been in this situation before, Warriors, you give them a chance,” Harbaugh said.

As Herbert limped to the sideline, Harbaugh said, he immediately decided that Herbert would not return to the game even if he asked him to.

“Justin is the guy you have to hold back with because you never have to talk him into anything,” Harbaugh said, “but you have to hold him back.”

Herbert said he was confident he could play next Sunday against the Kansas City Chiefs. Heinicke, who the Chargers signed just over three weeks ago, finished the game with 24 yards passing and completed both attempts. He was also sacked three times.

It was an injury-filled day for the Chargers’ stars. Outside linebacker Joey Bosa left the game in the first quarter with a hip injury after playing just two snaps. A back injury limited Bosa to just 14 snaps in last week’s win over the Carolina Panthers.

Left tackle Rashawn Slater, meanwhile, suffered a chest injury and spent most of the second half on the bench. Right tackle Joe Alt suffered an ankle injury in the fourth quarter and was limping noticeably after the game.