SAN DIEGO — That the Chargers’ starting secondary was practicing on Friday is a good sign. Because it’s in for a big test on Monday night.

The Chargers host the Pittsburgh Steelers, trying to win their second straight game and go to 3-0 at Qualcomm Stadium.

Three key Chargers defensive backs continue to practice after being out of Sunday’s win over the Browns.

Cornerback Brandon Flowers left with a concussion. Jason Verrett, the other starting cornerback, was a late scratch with a foot injury.

Strong safety Jahleel Addae (ankle) missed his third straight outing.

Without them, the Browns’ Josh McCown threw for 356 yards against the Chargers.

Flowers was a full participant in Friday’s practice.

Verrett and Addae were limited.

Steelers quarterback Ben Roethlisberger isn’t expected to play because of a knee injury. But his favorite targets will be active.

“It is going to be a really big challenge to stop them,” Flowers said. “Everyone knows about Antonio Brown and that he’s a great playmaker.”