I need help on how to defend a bigger post player than me?

I'm a 6'5 basketball player who plays post for my high school team, but on my aau team i play more of the 3 guard so im capable of playing both inside and out. In two weeks i have to guard a 7'1 german who weighs around 260. Now I'm not small weigh around 200 and am somewhat muscular, I can get up and have a 32 inch vertical but I really need some advice on how to guard this kid because from what I hear he's not the most coordinated all he really does is just bring a presence and a fear into the other team, He's also a big body and he blocks alot of shots. they also have another kid whose 6'10 so they're a big high school team. Any Advice?