Yes he's just fine.
I came home from work that day early to see how he was with the intentions of going straight to the vet if he was showing any signs of illness. He's absolutely fine, back to his old self, no more whining over the pulled muscle, no signs of any kind that the advil harmed him....no problems. Phewwwwww! Got off easy there. Next time I won't be putting ANYTHING into his mouth without talking to his vet first.
Thanks for the advice!