THOUSAND OAKS, Calif. -- In the midst of a three-game losing streak, the Los Angeles Rams have suffered a string of injuries that could cause depth concerns at several positions.

On Monday, Rams coach Sean McVay announced veteran cornerback Aqib Talib will be placed on injured reserve because of fractured ribs and left guard Joe Noteboom will undergo season-ending surgery after tearing the ACL and MCL in his right knee.

Safety John Johnson III has a right shoulder injury. He will seek further testing and opinions, but it could sideline him indefinitely.

"This is a challenging time," McVay said. "But it's not something that you're going to let be deflating."

Rams running backs Todd Gurley and Malcolm Brown are considered day-to-day, McVay said, ahead of their Week 7 matchup against the Atlanta Falcons.

Gurley was inactive last Sunday in a 20-7 loss to the 49ers because of a left thigh contusion, and Brown, who started in Gurley's place, was slowed during the game because of an ankle injury.

Talib will be sidelined for at least eight weeks before he is eligible to return from IR. Each team can activate only two players from IR.

A 12th-year pro in the final season of a two-year, $19 million contract, Talib did not practice last week and was inactive 49ers, after suffering a rib injury in a Week 5 loss to the Seattle Seahawks. Last season, Talib also was placed on injured reserve after he suffered an ankle injury in Week 3 that required surgery. He returned in Week 13.

Cornerback Troy Hill started seven games in Talib's absence last season and started again last Sunday. A fifth-year pro, Hill finished with four tackles and a pass deflection. He is expected to maintain the starting role with Talib out.

Defensive end Michael Brockers said the defense would "take a big hit in our leadership," in losing Talib, who plays in a secondary that includes safeties Eric Weddle and Johnson and cornerbacks Marcus Peters and Nickell Robey-Coleman.

Noteboom's injury leaves the Rams thin on the offensive line.

"That's a big loss," McVay said about the first-year starter. "He made a lot of progress in the early stages of this season."

Offensive guard Jamil Demby replaced Noteboom after he was sidelined against the 49ers, but McVay said the starting position would be evaluated moving forward.

"We'll look outside and see if there's maybe some guys available to add some depth, but we'll fill the starting spot from inside," said McVay. "Jamil has had a chance to play a lot of snaps, and David Edwards is a guy that we have a lot of confidence in, so those are things that we're going to work through."

The Rams selected Demby from Maine with a sixth-round pick in 2018. He played throughout the preseason and started Week 3 when right guard Austin Blythe was out because of an ankle injury.

Edwards is a rookie who was selected in the sixth round from Wisconsin.

Johnson, a third-year pro who has two interceptions this season, appeared to injure his shoulder in the first quarter against the 49ers, but he returned later in the game. He finished with four tackles.

McVay said the second opinion that Johnson will seek will determine if he is available Sunday or if he will miss extended time.

If Johnson is sidelined, backup safety Marqui Christian, a fourth-year pro, will start in his place.

The Rams, coming off an NFC championship and a Super Bowl LIII appearance, are 3-3, and they have lost three straight for the first time since McVay took over as coach in 2017.

The Rams will play their next three games away from home over a month-long period, including matchups against the Atlanta Falcons, the Cincinnati Bengals in London and the Pittsburgh Steelers.

"I trust that we're going to be one of those teams that people seem to think that things aren't going that well, but I think our guys are continuing to believe," McVay said. "They're staying the course, and we're going to see this thing through."