#Jets’ secondary was doomed from the start

The Jets, who are not very good with a fully healthy roster, had five cornerbacks on the active roster — and three are rookies — for Sunday’s game against the Chargers in Los Angeles.

Their five corners combined for a total of 11 NFL starts.

The result was rather predictable in the 34-28 loss to the Chargers. Their secondary was toyed with all afternoon by rookie quarterback Justin Herbert.

Herbert, who completed 37 of 49 for 366 yards and three touchdowns, looked so comfortable in the pocket he might as well have been on a couch watching this game from his home as he mercilessly torched the Jets’ defensive backs.

His pass catchers — receivers Keenan Allen, Mike Williams, Tyron Johnson and tight end Hunter Henry — had their way with the Jets’ secondary, which was decimated with injuries.

Veteran starter Brian Poole was already out for the season with a shoulder injury.

Pierre Desir, one of general manager Joe Douglas’s supposed key offseason signings, was released last week.

And then, on Saturday, Bless Austin, another starter, was placed on injured reserve with a neck injury. Austin, who’d played in eight of the Jets’ nine games this season and had 43 tackles, three pass defenses and a forced fumble, missed practices last week with neck discomfort and never made the trip to LA.

That left the Jets ridiculously thin at cornerback with only rookies Bryce Hall, Lamar Jackson and Javelin Guidry along with Arthur Maulet and Corey Ballentine, who was picked up off waivers a week ago. Rookie Ashtyn Davis, a safety, also was used in coverage.

“All hands on deck,’’ Jets coach Adam Gase said with a nervous smile during the week.

When Maulet, with seven career starts, is your most experienced cornerback, this is not a recipe for defensive success. The Jets started three rookies in the four-man secondary Sunday.

Predictably, it played out the way you figured it would. Herbert was 23-of-31 for 277 yards and two touchdowns — in the first half. Allen 10 catches for 108 yards — in the first half. Williams had two catches for 52 yards and a touchdown, Johnson had one catch for 54 yards.

On Williams’ touchdown, he was covered by Maulet, who collided with safety Marcus Maye and that allowed him to jog into the end zone untouched for a 14-6 Chargers lead.

Herbert’s third touchdown pass went to Allen on a third-and-goal from the 8-yard line on which Jackson, the Jets rookie corner, had his back to the play and never saw the ball until Herbert’s pass landed between the 1 and the 3 of Allen’s jersey for a 31-13 Chargers third-quarter lead at the time.

“They’ve got some good playmakers at receiver in Keenan Allen and Mike Williams and Hunter Henry,’’ Jets defensive end Henry Anderson said.

“Those guys played as tight as they could, but we had a few penalties, and [the Chargers] have three guys to worry about,’’ Gase said of his young corners. “And the ball was coming out quick. We tried to change things up a little bit, but … ’’