Around here, one of the high school coaches has bought into the mantra, "Warm up to throw. Don't throw to warm up."
While that may sound good, it doesn't make sense physiologically.
The problem is that many people substitute static stretching for a good, dynamic warm-up (aka dynamic stretching).
In order to prepare for any athletic activity, it's best to gradually get the blood flowing and warm up the muscles before they are asked to perform at their maximum level.
I believe that long toss, if done properly, can be an excellent way to get a ballplayer ready to play a game.
By progressive long toss, I am talking about two players partnering up and starting out 20 or so feet apart. After each makes 5 throws, they widen out 10 feet. They continue this for 50 or so throws and until they are 100 or so feet apart.