Following up on the ongoing story. ... As MLive.com's Kyle Meinke reports, the Detroit Lions opened the season at nearly full strength. Three weeks later, they’ll be without five starters for their game on Sunday against the Atlanta Falcons -- including both safeties and three-fifths of their secondary overall.

Safety Kerby Joseph (hip), offensive tackle Taylor Decker (ankle), cornerback Emmanuel Moseley (hamstring/knee) and guard Halapoulivaati Vaitai (knee) have all officially been ruled out against Atlanta. Another safety, C.J. Gardner-Johnson, was moved to injured reserve earlier in the week because of a torn pec.

All of which leaves Detroit down at least three starters on defense and another two on offense, while top running back David Montgomery is doubtful to play because of a thigh injury.

Receivers Amon-Ra St. Brown (toe) and Josh Reynolds (groin) are listed as questionable, but expected to play.

On the offensive side, the Lions are back to playing musical chairs on their talented-but-injury-bitten front. Penei Sewell is expected to start for Decker at left tackle, while Matt Nelson will earn a second straight start at right tackle. At right guard, Graham Glasgow is expected to start for Vaitai.

There could be some movement in the backfield too, where rookie Jahmyr Gibbs is expected to earn his first career start. Montgomery is dealing with a thigh bruise he suffered against Seattle. He didn’t practice all week and is unlikely to play against Atlanta, although the Lions left that door slightly open by listing him as doubtful.

Even if Montgomery somehow is able to suit up, he’s unlikely to shoulder another workhorse load for Detroit. Gibbs, the 12th overall pick, seems destined to play his biggest role yet.