Injuries happen in the NFL. There’s no way to fully prevent them from happening.
But you can take the appropriate measures to help curb injuries. That’s what the NFL offseason is all about. Minicamps, OTAs, workouts, rehab, etc. — all of it is there to help keep NFL players in game shape and keep them ready for the upcoming season.
So if you take away the offseason, then you take away the opportunity for players to stay in contact with coaches, trainers, and doctors, which could have negative effects.
This year, there was no offseason. The Coronavirus literally reduced everything to virtual meetings.