"Relatively minor" in that he'll almost certainly completely recover from it, barring surgical complications of course. It's not like he's paralyzed, lost a limb, or even something like a kidney. It seems like a fairly routine injury, not unlike the one Milano suffered. "Serious" in the football sense, but not in the real-life sense. I would be shocked if it was a "career ending" injury for a guy who's 25.