Suppose Rondell White wakes up this morning and remembers how to hit and goes on a tear.
Suppose he hits .300/.350/.470 from this point forward. Would it be okay to say, "Since Rondell White got untracked on April 18th, he's had an OPS of .820." Or do we have to carry the 4-47 start around and never look at his numbers after that. Just wondering. Because I took a ton of grief last year for ignoring or rather breaking up a certain player's season into April and post April. I also took a little grief in breaking another player's season into first week of June and rest of the season.

C'mon, we already know the answer. If he's a "proven veteran hitter", you have to take whatever numbers make him look the best.
If he has less than 3 years service time, you can slam him for anything. ANYTHING.
FWIW, I'm still planning on charmining your abode. The worst thing, I knew it was coming. I knew it was a joke. But I still said, "REALLY!?!" with a little too much excitement. grr.
All I got wrong was the leave of absence thing. Otherwise, I'll maintain that it was accurate reporting.
If he finishes the season strong, you count that. You certainly can use that finish to glorify a person's season.