Tiger's a golf prodigy and has been driving the ball farther than most grown men since he was a teenager. So unless he was on the needle at 13, then I doubt he's juiced now. Why would he even think about wrecking what he's got going for himself?
for the sake of argument - we don't know what 15+ years of playing competitive gold has done to him. he might have injuries or deficits from the rigors of longterm training and playing.
one reason he'd consider it would be to recover from some ailment. Blowing up big might have been a fun side effect. I still stand by my belief he doesn't - but there are many reasons why he'd consider using.
And - I don't see it as "wrecking himself". Golf doesn't test for steroids, and anything he got wouldn't have to come from Joe Snitch, the local dealer. Tigerr would get HRT or test from his very expensive doctor and unless one of these two men opens his mouth, the world will never know. besides, even if PGA knew, no way they'd say anything. Tiger is very very good for golf.