As I said, I agree Matthews seems to be injury prone, but he's in prime physical age, so I don't buy the sweeping argument that all the injuries are related to having an older team vs. players that are injury prone like Stoli and Matthews. It plays a role but I don't think we have any conclusive evidence that age per se is the reason for 7 regulars being out and that it isn't a confluence of many different factors like luck, style of play, injury history, age, bad decisions etc.
No one ever claimed "
all the injuries are related to having an older team". That is a strawman
Matthews himself has played a lot of hockey - international tournaments, all-star games, etc plus more NHL games than anyone in his draft year in spite of his injuries. He in the top 25 among forwards for ice time since he came into the league. So he's older on the wear and tear scale for a 28 year old. 28 is roughly the year before NHL forwards tend to start to decline. It is very probable with his wear and injury history that Matthews has begun his descent. Doesn't mean he can't have another good year but in light of his injuries, his trend is probably downwards from last season largely due to his injuries.
Like any general thought, there are exceptions like John Tavares. Some of that is due to his devotion to taking care of his body. Nylander with his aversion to hitting or shot blocking has probably aged better than average. But statistical trends for points or games played or time on ice show the general decline with age and wear and a hunk of that due to injuries.
Older teams are more injury prone because of the wear and tear of their older players playing many hockey games and getting more ice time. Some injuries to back, neck, hip, shoulder, knee, head (concussions), groin, etc are cumulative or never fully heal - including after surgery. In some case, arthritis creeps in - which is part of the reason some slow down. etc. A number are related to overuse and repetitive wear. And older players tend to take longer to heal and therefore miss more games due to injury. Tanev is likely out longer because of the number of whacks to his head over his career.
All teams, including their young players have injuries. Older teams tend to have more injuries and games lost to injuries.
For the Leafs, they're particularly vulnerable in goal and defense. Stolarz 31 with 3 significant knee surgeries and Woll who I suspect has not had an injury free season in his pro career. The Leafs dmen have 6 of 9 31 years or older and their top five are in the top 70 for time on ice among dmen over the last 12 years. So they're likely to have more injury trouble there as the season goes on.
Treliving had to know all that when he was messing with the team "DNA".