Niners S Jaquiski Tartt (groin) and S Jimmie Ward (quad) remained out of practice Wednesday after missing Sunday's win over the Patriots. Tarvarius Moore and Marcell Harris started in their places against New England and tied for the team lead with 5 solo tackles. Each would be in play for IDP use against a pass-heavy Seattle team this week if Tartt and Ward sit again. Moore is the Ward replacement and Harris for Tartt, though their in-game roles have been fairly interchangeable. Elsewhere on the defense, LB Kwon Alexander (high-ankle sprain) remained out of practice Wednesday. His absence would keep Dre Greenlaw in a full-time role.

Niners CB Emmanuel Moseley (concussion) is questionable for Sunday's game against the Rams. He finished the week with 2 full practices, though, and looks on track to play. We'll confirm Moseley's status Sunday.

Niners HC Kyle Shanahan said this week that LB Kwon Alexander suffered what the team believes to be a high-ankle sprain in Sunday's loss to the Dolphins. "They're not sure of the severity of it," he said. "It could be a minor one for whatever that means." Alexander didn't miss any of the game, but he did miss Wednesday's 1st practice of Week 6. We'd have to bet on him at least missing this Sunday night's game against the Rams, which should mean near-full playing time for LB Dre Greenlaw. We'll keep an eye on the situation this week.

The 49ers have ruled CB Emmanuel Moseley (concussion), CB Dontae Johnson (groin) and CB K'Waun Williams (knee, hip) out for Sunday's game against the Dolphins. CB Ahkello Witherspoon (hamstring) is also questionable. He missed last week's game against the Eagles but managed limited workouts this week. We'll check on Witherspoon's status Sunday, though he's not much of an IDP factor either way. The big takeaway here is that the Niners will miss at least 4 of their top 6 corners -- with Richard Sherman still on IR. That can only help Miami QB Ryan Fitzpatrick, WR DeVante Parker and TE Mike Gesicki.

The 49ers have ruled CB Emmanuel Moseley out for Sunday night's game against the Eagles with a concussion. The team has also ruled CB Ahkello Witherspoon out (hamstring) and deemed slot CB K'Waun Williams questionable. With Richard Sherman already out, San Francisco will be missing at least 3 of its top 4 corners for the game. The question, of course, is whether the banged-up Philly offense can exploit that weakness.

Niners CB Emmanuel Moseley left Sunday's win over the Giants early with a concussion. We'll see whether he has a chance to make it back for the Week 4 Sunday night clash with the Eagles. Dontae Johnson took over Moseley's spot after he departed, finishing with 2 tackles and a pass breakup.

Niners DE Dee Ford is expected to miss his 2nd straight game Sunday, according to NFL Network's Tom Pelissero. The injury was listed as a neck issue for Week 2, which Ford missed. Pelissero reports it as a back injury that needs to "settle down" and "may take some time." Ford has spent a lot of time dealing with various ailments since joining the 49ers last offseason. He's fine to dump in most IDP redraft leagues until this current injury "settles." The injuries to both him and DE Nick Bosa leaves room for new 49er Ezekiel Ansah and DE Kerry Hyder to see plenty of snaps.

The MRI has confirmed that 49ers DE Nick Bosa tore his left ACL in Sunday's win over the Jets. So his season's done. It's also the 2nd ACL tear of his football career. Bosa previously tore his right ACL in high school. That at least means Bosa has been through the process. We'll see about his progress during the offseason. The Niners, meanwhile, agreed to a 1-year deal with DE Ezekiel Ansah to help fill the void.

Niners DE Nick Bosa left in the 1st quarter of Sunday's game against the Jets with a left knee injury. The team ruled him out for the day in the 2nd quarter. We'll see about the severity, as Bosa is likely headed for a Monday MRI.

Update: HC Kyle Shanahan said after the game that it's "most likely an ACL," according to NBC Sports' Matt Maiocco. That probably means a tear. We'll await Monday confirmation, but that would be a big blow to San Francisco's defense.

The 49ers have ruled DE Dee Ford (neck) out for Sunday's game against the Jets. We'll see about his status heading into Week 3.

Niners DE Dee Ford is questionable for Sunday's game against the Jets. He missed the final 2 days of practice this week with a neck injury, making Ford an iffy bet for IDP lineups even if he's active.

Niners DE Dee Ford missed Thursday's practice with a neck issue. The veteran didn't show up on the Wednesday injury report, so this appears to be a new ailment. We'll see about his status for Sunday's visit to the Jets.

The 49ers have placed LB Fred Warner on the COVID-19 reserve list. It's not yet clear whether Warner has tested positive or merely been exposed to a COVID-positive person. If Warner displays symptoms, his Week 1 availability would be in jeopardy. Other players have come off the list in as little as a day or 2. We'll keep an eye on the star LB's situation as the opener approaches. If Warner misses any games, Dre Greenlaw would likely take on a 3-down role.