Yeah since cartilage obviously isn't muscle there's no direct way to strengthen that by weightlifing even though it's somewhat reinforced by strong abdominal muscles.
My biggest concern above the others is this injury, where I'm unsure that we get a 100% or even 90% Donald on game day vs Packers. Sure 90% is better than most others, but I really don't want him operating at less than 100 if we are to have a chance to win.
I'm recalling a long ago playoff game where a certain defensive star by the name of Jack Youngblood suffered that broken leg. In the following title game and SB he wasn't the destructive force that I was accustomed to. Sure it was better to see him out there than MIA but I tell people what a pass rush we'd have in the SB with him at 100%. Bradshaw would have little time to launch those 2nd half bombs. What if, woulda, coulda, I know.
And we know a broken leg is more serious than torn rib cartilage (a little more at the closest) but it's still cause for concern. The effect on a player could be similar though both injuries are totally different (again, obviously). He had labored breathing after the injury which looked like broken ribs or a punctured lung. Labored breathing could screw up his stamina big time. The motor needs to be constantly running. Also don't want the enemy team poking at it during the game. In times past that would happen when a player has a known injury so there could even be a subtle rib jab here and there.
My temporary solution.... flak jacket.