Only for headaches. Can't use them for muscle injuries or something because if you don't feel the hurt, you're most likely to make it worse!
Then again, you probably wouldn't use asprins for muscle injuries but that's another issue :D
I believe he'll choose Argentina because he feels more connected to that country (he was born there) and because he thinks Argentina stands better chances of winning trophees.
Though I suspect he won't say the latter reason out loud!