Report: Herbert's X-rays negative on injured ankle

X-rays on the injured ankle of Los Angeles Chargers quarterback Justin Herbert came back negative, a source told NFL Network's Ian Rapoport.

Herbert will reportedly continue to be monitored this week after aggravating his injured ankle in Sunday's loss to the Pittsburgh Steelers. He exited Sunday's game in the third quarter and didn't return.

Herbert left the stadium in a walking boot, though head coach Jim Harbaugh said postgame he didn't have an injury update at the time.

The 26-year-old passer was already dealing with a high ankle sprain coming into Week 3 and was questionable to suit up against the Steelers.

Taylor Heinicke filled in for Herbert for the remainder of the game, completing both of his two pass attempts.

The 2-1 Chargers take on the 3-0 Kansas City Chiefs in Week 4.