He's taking it off for personal reasons, it's best to just leave it at that. Only he and who he decides to discuss the reasons with knows what they are. He's afforded the right to take as many weeks as he wants off. Just like any other bowler, if they have an exemption secured (which he does by virtue of a US Open title last year) he can take time off even if it's because Tracy forgot to pack his favorite shirt.
The only ones who "can't" afford to take time off are the bubble boys, and that's if they want to fight to keep their exemption.
He'll be back fresh and ready for his US Open title defense
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Justin Buford