What's the sample size of the stats? You're only at 10/20 blinds so they are likely worthless unless you haved played with him before. As played, I would lean towards calling just because I think my A high might be good here a fair bit of the time. I am not calling just for the draw but because I think at least a good portion of the time I am going to have the best hand. He could be cbetting with a wide range of overcards that you beat. I would call his bet, then see what the turn is like, If I hit the straight I am never folding (J9 is too unlikely even if we just hit the 6), if he keeps betting I will likely keep calling for a few reasons. The first is that at 10/20 blinds I am not risking a huge amount of chips, secondly A high may be good, thirdly there are alot of outs to what is essentially the nuts in headsup, and fourthly, I want him to know early on that I am not just going to fold simply because he barrels at me, in the hopes that he will start barrelling lighter for value against me when I have a hand. For a small amount of chips, I am happy to set up more of a calling station image early. Of course, this isn't just blindless calling - A9 has outs to the nuts here + high card value + the A out is likely alive.

I'd generally call, I don't expect him to ever bet/fold a better hand on the flop. We can showdown the best hand fairly often if he checks the turn.