Yeah, there's an ebb and flow with injuries. You may start the season with everyone pretty healthy for the first few games, then out of the blue, your whole secondary is out with questionable to doubtful injuries! Yes that happened to me not too long ago. I think I was suiting up just 40 or 41 players for two or three games.
And I have had a time when both QBs were too hurt to play. That was a fun couple of games!
It's just one of those interesting facets of managing the team. At times frustrating, but pretty realistic for the most part.