El SEGUNDO, Calif. -- Los Angeles Chargers quarterback Justin Herbert was diagnosed with a plantar fascia injury in his right foot after Wednesday's practice that will put him in a walking boot for two weeks, the team announced Thursday.
After the time in the boot, Herbert will be on a "gradual return to play protocol" and is expected to be ready for Week 1, the team said.
Following Thursday's practice, coach Jim Harbaugh said he had "no update" on Herbert's status, referring to the team's statement. When asked if he was concerned about his quarterback missing time on a team implementing essentially a new offense, Harbaugh said it's still "full steam ahead."
"The preparation, the work continues," he said. "He's not on the field, in practice, but in the meeting room, still in the training environment, that chemistry that rapport you build with those position players, with his teammates, that continues."
Herbert moved without any limitation through the first week of camp. On Wednesday, he sprinted into the end zone for a score in an 11-on-11 period and celebrated with teammates, which made news of his injury all the more surprising.
When asked if he knew if Herbert was injured on a play or if he had been dealing with foot pain prior to Wednesday, Harbaugh said he was "not qualified" to know that information.
Herbert has been one of the most durable quarterbacks in the NFL through his first four seasons. He started 62 consecutive games, the second-longest active streak by a quarterback, before a fracture to his right index finger in Week 14 last year ended his season. Herbert's backup, Easton Stick, went winless in the Chargers' final four games.
Stick, Max Duggan and Casey Bauman are the other quarterbacks on the Chargers' roster. At Thursday's practice, the group struggled. The defense dominated the day, and Duggan ended the practice with a pick-six to rookie cornerback Tarheeb Still.
"It was a very good day for the defense, and as I told them, I was very impressed with the defense," Harbaugh said. "And the offense, yeah, just keep chipping away."