SANTA CLARA, Calif. -- For the past two weeks, San Francisco 49ers coach Kyle Shanahan has strolled to the lectern on a Monday and begun his day-after-game news conferences by offering extensive injury updates. With more names added, Shanahan actually had to have a written list of each player, his injury and his potential for a return when he spoke this week.

What that list doesn't contain is an explanation for why Shanahan's team has been ravaged by injury in his first year at the helm.

"I was kind of joking last week when I said you've got to ask God, because, I mean, we can guess, but no one knows for sure," Shanahan said. "I know we've been going for a while. We've got to get through this week, and we'll have our bye week after that. I know our guys have been playing real hard. We've been playing some long games and battling and some physical games, and injuries happen. I've never been a part of a team where it's been like this, but teams do have to deal with this type of stuff all the time, especially this time of the year."

Indeed, if there's a guarantee during an NFL season it's that injuries are going to hit every team. But rare is the case in which one team is hit as hard as Shanahan and the Niners are right now. With offensive tackle Garry Gilliam (knee) going on IR earlier on Tuesday, the 49ers have now had 23 players spend at least some time on injured reserve since training camp began. Many of them remain there, some have been released with injury settlements and defensive lineman Ronald Blair has returned to the active roster.

Included on the list of those out for the season are starters such as receiver Pierre Garcon, defensive ends Tank Carradine and Arik Armstead, safeties Jaquiski Tartt and Jimmie Ward, linebacker Malcolm Smith and guard Joshua Garnett. None of those players made it past Week 9 in the first season under Shanahan.

Making matters worse, that doesn't account for the many key 49ers such as left tackle Joe Staley, defensive end Solomon Thomas, fullback Kyle Juszczyk and linebacker Reuben Foster who are dealing with week-to-week injuries.

To their credit, neither Shanahan nor the Niners are willing to use the injuries as an excuse for their dreadful 0-9 start, though they can realistically acknowledge that the missing pieces are playing a role in their inability to get over the hump.

"It's tough," safety Eric Reid said. "That's what happens in football. The guys that are healthy, we've just got to make sure that we take care of their body. But again, nobody cares. We've just got to get the job done with the guys we have."

For a team like San Francisco going through a rebuild, just how far it has to go to get back to contention might not be as evident when it is fully healthy and has all 22 projected starters in the lineup. The difference between the best starting 22 and the worst in the NFL usually isn't a substantial gap. When injuries creep up, though, the margin between the best and worst is more easily exposed.

That's precisely what's happening to the Niners right now and why they were competitive for most of the first half of the season before losing by double digits in each of the past three games.

While all those injuries are creating opportunities for the 49ers' young players, many were already getting plenty of snaps. In some instances, the injuries have forced the Niners into playing some young players who might not have been considered ready to contribute in such important and extensive roles.

"Now [there are] a lot of guys are getting opportunities to play that you're hoping to have more time to develop them," Shanahan said. "It's a huge opportunity for some of the guys. Some of the receivers you've seen out. Some of the tight ends the last couple of weeks, O-linemen. There's been guys getting opportunities. When we lost those five close ones, you look at the team and you can see, 'All right these guys are getting a lot better and we're going to get there.' A lot of those guys you've missed.

"So, you've had some guys come up who've gotten opportunities to play and I do think it helps you, whether they're going to be starters next year or whether they're going to be rotational players."

To Shanahan's point, the opportunity to give some of those players a chance to play can be helpful in evaluating them, but it's also something of a double-edged sword because having to force players into action if they aren't ready can also be damaging to their confidence. In addition, playing for a team without so many key pieces can make some players look worse given what they have around them, (see Beathard, C.J.).

In the Niners' case, the sheer amount of injuries has also forced them to play a variety of players signed off the street with little chance to be part of the team's long-term plan. Mixing in those players with youngsters they hope will be contributors soon can also create a fragile mix.

One way or another, Shanahan and the Niners have seven more games to figure out what they have for 2018 and beyond. But it's also worth noting that the current circumstances will make determining where those players fit a more difficult proposition.

"The main thing is that we've got to add to our team, the people that are out there starting and to the depth off of it," Shanahan said. "Everyone goes through an NFL season, everyone has injuries. We need to build this the right way, so when you do have injuries that you have people who can step up and play. That's what we're going through right now. Hopefully these guys who are playing now and getting some opportunities that they maybe wouldn't have had if we'd stayed healthy. Hopefully that will make them better and give us some more depth going into next year."