He was actually 17 when he had the emergency appendectomy that caused that 3-month layoff. I'm not sure I consider a 4-day absence anything noteworthy. The ankle injury at Southampton was pretty serious and he missed a big chunk of time, though some of it was almost certainly due to his interest in leaving the club.
I think it's funny that saying we should buy another CB because our 22-year old potential star of the future has yet to have a healthy season during his 4 years at the club. I get that there's this idea that we'll impede his progress if we buy someone like De Ligt, but he's 3 years older than De Ligt, and if Gomez is good enough, he's good enough. Virgil will need some rest and we're going to play 60-some games next year; there are plenty of games to go around.
We are champions of Europe, coming off the third-highest points total in a PL season. We have the money and the cachet right now, and the opportunity to cement our back line for the foreseeable future. I realize it's not 100% up to us but how hard a sell could it be, especially considering he's VvD's international teammate and CB partner.