RB's and WR's are finely-tuned athletes who are built for speed, for the most part. but that also means they can be more susceptible to pulled muscles, especially hamstrings.
it's ironic in light of Fleck's comments at B1G media day:
Darius Taylor, a running back, who I think arguably had one of the better seasons at running back, but he just didn't play a lot. In the off-season, Darius spent a lot of time getting to know his body, working with our sports science team, our nutritionists, our dieticians, our strength staff, our trainers, to make sure he has a really healthy 2024 and do everything he possibly can.
in other words, you can do all the right things, take every precaution, and players can still get injured. some athletes are just built differently than others. linemen generally don't pull hamstrings. but you wouldn't want a RB who is built like a lineman.
or to use a Pat Reusse quote: "you can't pull fat."