The best thing you can do is take away his strengths. That may mean forcing him to go left if he's a right handed player, or sagging a little if he can't shoot to play him for the drive. Defense not only takes heart, desire, footwork and balance, but also your BRAIN! Study the habits of your offensive player, try to take away these normal moves, and force him to make moves he's not typically used to.
Then, whether your man shoots it or someone else, block him out and keep him off the boards.
Hope this helps. I am in the process of putting together some defensive videos for players like yourself who are not sure how to best play defense. If you are interested, email me at firstname.lastname@example.org
Yo, what up fools?: It's me, " THE MAN " , Zac Ryan. Even though I'm a cartoon character, I can still ball chump! So if you like basketball, then come check me out and read all my comic strips at: