Really? Did he mention any of the young players in particular?
None of them have played massive amounts of football. Ben Stevenson for example has started 23 games, I wouldn't say that's an awful lot for a 19 year old touted to be worth Millions.
Jodi Jones has started 10 games. That is 4 less than the old boy Nathan Clarke.
If the young players really are "burning out" I'd say its a lot to do with fitness and management of them. Same with "losing" mentality, any person being played to play a sport should be ashamed to have one of those, you get Sunday league teams who get dicked 10-0 week in week out who show more fight and passion.
Poor 19 year old footballer who has had to play over 20 games, there are 16 year olds who play Saturday's and Sundays who then go to work all week and train in the evenings. There are probably 40 year olds who do it too, they won't have access to physios, nutritionists, sports scientists etc either.