San Francisco 49ers activate four defensive backs from COVID-19 list prior to showdown with Los A...

LOS ANGELES -- About 24 hours before a season-defining game against the Los Angeles Rams, the San Francisco 49ers welcomed back most of their secondary on Saturday afternoon.

After placing five defensive backs on the reserve/COVID-19 list earlier this week, the Niners activated four of them over the past couple of days, including cornerbacks Ambry Thomas, K'Waun Williams and Dontae Johnson and starting free safety Jimmie Ward. Thomas was activated on Friday, while Ward, Williams and Johnson were cleared on Saturday.

Additionally, the Niners activated starting cornerback Emmanuel Moseley (ankle) from injured reserve on Saturday after he returned to practice on Wednesday.

That means the Niners should have their starting secondary intact against Matthew Stafford, Cooper Kupp& Co. on Sunday with Moseley and one of Thomas, Johnson or Josh Norman starting at corner and Ward and Jaquiski Tartt at safety (assuming Tartt, who is listed as questionable, is able to play through a shoulder injury).

The 9-7 49ers enter Sunday's game at SoFi Stadium needing a win or tie against the Rams or a New Orleans Saints loss or tie against the Atlanta Falconsto clinch a playoff berth.

All of that comes after a week in which the Niners were scrambling just to have enough defensive backs available to practice.

But defensive coordinator DeMeco Ryans said all of the defensive backs who were on the reserve/COVID-19 list were able to stay in tune with the game plan from a distance, even if they weren't on the practice field.

"The best part about it is we've had all our meetings virtual," Ryans said. "They understand the game plan. They're able to ask questions about the game plan. Our guys, they've been locked in mentally and the guys who are on that list, they've played a lot of ball for us. They understand our scheme, what we're trying to do defensively, and those guys, we'll be grateful to have them back as soon as we can get them back. But I think there won't be any mental hurdles for our guys. They'll be able to plug right back in and get out there and help us."

With that quartet back, the only two Niners remaining on the reserve/COVID-19 list are running back Raheem Mostert (who is on injured reserve with a knee injury) and cornerback Deommodore Lenoir, who could still be cleared on Sunday morning.

In addition to those moves, the 49ers elevated cornerback Darqueze Dennard and linebacker Mark Nzeocha from the practice squad and designated linebacker Curtis Robinson as a COVID-19 replacement from the practice squad.

One move the 49ers did not make: Quarterback Nate Sudfeld was not activated from the practice squad, yet another indication that Jimmy Garoppolo will be available alongside Trey Lance in some capacity against the Rams.