The San Francisco 49ers stayed relatively injury free during their 23-17 preseason loss to the Indianapolis Colts Saturday. But there were a few injury updates from head coach Kyle Shanahan, who spoke with reporters Sunday evening.

The San Francisco 49ers have dealt with a number of key injuries during 2018 training camp and the preseason, and their first exhibition game against the Dallas Cowboys saw more than a few players go down with notable injury setbacks.

There weren't quite as many during the Niners' 23-17 loss to the Indianapolis Colts in Week 3 of the preseason, although head coach Kyle Shanahan clarified a couple of injuries suffered by players during the game.

Cornerback Jimmie Ward exited the game with a quad injury. Linebacker Reuben Foster suffered a concussion, and the 49ers also suffered injuries to wide receivers Aaron Burbridge and Dante Pettis -- a hamstring and bruised knee, respectively, according to Shanahan.

"They all should be good for Week 1," Shanahan said on a conference call with media members Sunday. "But we're definitely not going to have them this week."

San Francisco wraps up its final preseason game of 2018 against the Los Angeles Chargers on Thursday, Aug. 30. Most, if not all, of the starters likely won't play during the bout.

When asked if he anticipated whether or not all three players would make the 49ers' 53-man roster ahead of Week 1, Shanahan was relatively non-committal.

"I don't know," Shanahan responded. "We'll see how these final four days go and how the final 53 fold out. We've still got four more days to decide this, and a lot is going to have to go into this. So we're not there yet with the final 53."

One of the players in question is Ward, who has largely struggled this preseason. With a history of injury (Ward has landed on season-ending injured reserve in three of his four years at the NFL level), one had to wonder if Shanahan had grown frustrated with the fifth-year defensive back suffering yet another injury setback.

"I don't want to say 'frustration', because that would be a negative towards Jimmie," Shanahan said. "It's just unfortunate. Jimmie works really hard, and I love Jimmie as a player. And he's very tough. He has gotten hurt a lot, but I don't question any of those. Jimmie throws his body around, works very hard and it's just been very unfortunate. ...

"He's had a tough run of luck here and, hopefully, that will start to get better for him."

Ward isn't expected to start in 2018, leaving the boundary duties to Richard Sherman and Ahkello Witherspoon, while K'Waun Williams starts at nickel. But Ward's ability to play any cornerback spot, as well as at safety, makes him a valuable backup option. Even if his $8-plus million on his fully guaranteed fifth-year option is costly for reserve duties.

The 49ers played around with their linebacking corps a bit during the game, working a foursome of Foster, Brock Coyle, Malcolm Smith and Fred Warner in a regular rotation. Smith exited relatively early, however, although Shanahan indicated the move was more precautionary, as Smith had been dealing with a hamstring issue earlier in the preseason.

Foster is now in the NFL's concussion protocol, along with offensive tackle Garry Gilliam, and Shanahan didn't sound enthusiastic about either seeing playing time on Thursday.

"I don't know," Shanahan continued. "Reuben is in the protocol. You never know how that stuff goes. He definitely has a chance, but he's day-to-day with that stuff and we'll see how the protocol goes."

Foster will undergo his NFL-mandated two-game suspension to start the regular season, meaning the 49ers can take their time with his recovery.