Tournament play - he min bet the flop - he either has a weak ace or a 9x - possible trips but I doubt it...if he has 89 you're in trouble on the turn. 9T you're good - you have to bet the turn probably a bump up to 800 to see where you're at. He's the chip leader and is much more likely to bet middle pair weakly and call to see if he can two pair or trip up to beat you.

As far as tourney play goes, if you're going to play a weak ace here you at least have to weak bet the flop...owise you get yourself into this goofy situation...

I would not apply this to cash ring 9-10 max as the obvious answer has already been stated - fold preflop.