You might be able to see it hit the bat but only as a spectator. We could probably have a very long discussion of how we guess this actually works. Suffice it say that it can't hurt to track it as long as possible, yet at the same time tracking it longer would probably be near the bottom of my list of importance with regards to making good contact.
I hope you don't tell the players that. The most important aspect to being a great hitter is seeing your target (the ball) as well and as long into the zone as possible. I don't care how good your swing is, if you shut your eyes off you will not hit as consistently as you should.