Garoppolo did not practice Wednesday, and he probably won't be able to practice later in the week, coach Kyle Shanahan said. That means backup Nick Mullens will work with the starting unit and is most likely to start against the New York Giants on Sunday.
"I'll be surprised if Jimmy gets back later in the week," Shanahan said. "I know he's still pulling to do it. But Nick is ready to go. ... Nick has got a lot of playing time with us, and 2018 prepared him for moments like this. He always does a good job in practice, and [we're] excited to see him get his opportunity."
Garoppolo suffered a high ankle sprain during last week's win over the New York Jets. He played on it through most of the first half but did not return to the game after halftime. On Monday, Shanahan had indicated that Garoppolo could play this week because the sprain wasn't as severe as first feared.
If Mullens does get the nod as expected, it would be his first start since Dec. 30, 2018. That season, Mullens started the final eight games after Garoppolo suffered a season-ending left ACL injury in Week 3; Mullens replaced C.J. Beathard in Week 9.
In 2018, Mullens threw for 2,277 yards with 13 touchdowns and 10 interceptions for a passer rating of 90.8. While he mostly managed the game last week against the Jets in relief of Garoppolo, he did go 8-of-11 for 71 yards with an interception.
"When he got thrown in the fire, he played very well with little experience in practice," Shanahan said. "I know our players believe in him, and he'll be fine."
The question for Mullens: How much of his supporting cast will be available against the Giants?
Tight end George Kittle, who is dealing with a sprained left knee, was limited in practice Wednesday. Linebacker Dre Greenlaw (bruised thigh) also was limited. Defensive tackle D.J. Jones (ankle) was good to go.
Ford, who was inactive last week after dealing with neck spasms, got further testing on what is now considered a back injury. Shanahan said Ford is undergoing treatment, but there is no specific timeline for a return because of the unpredictable nature of back injuries.
"When you're dealing with a back injury, you don't really know the timetable," Shanahan said. "I know he's gotten some medicine this week that we're hoping helps. But that's a wait-and-see approach, so each day you're looking into him to see how it goes. I'm sure it's a long shot [to play] this week, but there is no timetable because you have got to see how the medicine reacts and how it helps him."
Coleman, like starting running back Raheem Mostert, is dealing with a sprained knee. Shanahan said Coleman's injury is more severe than Mostert's and could land him on injured reserve later this week. Mostert did not practice Wednesday, either.
"I'm expecting Tevin to be out a little bit," Shanahan said. "I'm expecting about four weeks, so maybe possibly an IR candidate here to return toward the end of the week. He's worse than Raheem is."
With Coleman and Mostert almost certainly out, the Niners will turn to Jerick McKinnon and Jeff Wilson to handle the primary running back duties. Undrafted rookie JaMycal Hasty could be a candidate to be called up from the practice squad for Sunday after the Niners used one of their practice squad "protections" on him this week.
The 49ers made a handful of roster moves Wednesday. They placed defensive linemen Nick Bosa and Solomon Thomas on injured reserve with torn left ACLs, signed defensive end Ezekiel Ansah and promoted end defensive end Dion Jordan from the practice squad to the active roster.
Meanwhile, the team is still awaiting word from the league and the NFL Players Association, with regard to their concerns about the playing surface at MetLife Stadium, where they suffered six lower-body injuries last week against the Jets and will play again this week against the Giants.
"The NFL and NFLPA is having people look at it right now," Shanahan said. "So we'll go with that. If they don't find anything, you go out there and play. Other people tore their ACL in this league last week and they weren't all on turf. So you know how we felt about it. We'll see what the professionals say, and hopefully we'll learn something."