The San Francisco 49ers already suffered a key setback to running back Matt Breida during their Week 7 home contest against the Los Angeles Rams, who exited earlier with an ankle injury.

And early in the third quarter, the Niners appeared to have lost starting free safety Adrian Colbert to a lower leg injury.

Colbert and 49ers cornerback Ahkello Witherspoon were attempting to defend a deep pass from Rams quarterback Jared Goff intended for wide receiver Brandin Cooks. Witherspoon appeared to intercept it, but officials ruled it incomplete. Yet Colbert landed awkwardly on his right leg, which appeared to bend back behind him.

After spending considerable time down on the field, the 49ers training staff called for the cart and San Francisco's second-year defensive back needed to be carted off the field.

He's officially questionable to return, which seems a bit more on the optimistic side.

The 49ers were forced to place the rookie, D.J. Reed, into Colbert's place at free safety. Reed previously took over nickel duties for K'Waun Williams, who exited briefly with what looked like a lower leg injury but managed to return.

San Francisco currently trails Los Angeles 25-7 with just over eight minutes remaining in the third quarter.