ST. LOUIS -- Marlon Moore, who had only one catch as the 49ers' No. 3 wideout through three games, is inactive for Thursday night's game, and former Chiefs receiver Jon Baldwin instead will suit up for the first time.
Also bolstering that embattled receiver unit will be Vernon Davis, who is active after missing Sunday's game because of a hamstring injury.
Linebacker Patrick Willis (groin) and cornerback Nnamdi Asomugha (knee) won't play because of their injuries. Michael Wilhoite will make his first career start, in place of Willis.
Running back LaMichael James is active after missing the first three games with a knee injury, and he'll most likely serve as the return specialist instead of Kyle Williams, who's also active but has been battling rib and knee injuries.
Cornerback Darryl Morris, promoted from the practice squad earlier this week, is active and will suit up. But the 49ers likely will use Tramaine Brock or Perrish Cox in Asomugha's spot as the No. 3 cornerback.
Also inactive for the 49ers are quarterback B.J. Daniels, wide receiver Chris Harper, fullback Owen Marecic and guard Joe Looney. Moore is a healthy scratch, it's believed.
The Rams' inactives are running back Isaiah Pead, guard/center Barrett Jones, guard Brandon Washington, guard/tackle Mike Person, tackle Rodger Saffold, tight end Mike McNeil and defensive end William Hayes.