Through eight games as a pro, he's averaging 18 points and more than 6 assists a game, and looks to have quickly established himself as one of the better young point guards in the league.
When game-planning for the Blazers, teams will be looking to diminish his effectiveness as a threatening scorer and efficient playmaker.
So what's the best approach?
Maybe the simplest, most obvious answer I can think of: Take the ball out of his hands.
Not physically, unless you have some like Jerome "Junkyard Dog" Williams who would just rip the ball out of people's hands—but by using traps and random pressure to force him to give it up.
Let's first talk about taking away his perimeter game.
The top priority must be to play up on him. Nobody can afford going under screens. He's just too good of shooter when given room to launch.
Below, we see Steve Nash defending Lillard but sags too far back. Lillard gets a ball screen, and all of the sudden Nash is a good five feet from his man. Lillard steps behind the screen, rises and fires. Completely open look.
Because Nash goes under the screen, he gives Lillard all the room in the world to set his feet and take an open jumper. Take a look at all that space between the two.
Lillard shot 40 percent from downtown as a junior at Weber State, and he offers NBA range as a rookie. He'll destroy defenders who aren't quick, aggressive and physical.
The best way to take away his effectiveness off the dribble is simply trapping at half court. The Dallas Mavericks did this to him the other day, when he shot 2-for-13 from the floor.
Allowing Portland to spread out and set up will make it easy for Lillard to pick the defense apart. Below is a setup that resulted in Lillard taking his man all the way to the basket.
I added the arrows for what the defense should have done in order to make Lillard uncomfortable as a ball-handler.
By doubling Lillard up top, it forces him to give it up early. The defense must then react and rotate accordingly. There's no science to rotation—just being aware of your surroundings and keeping your head on a swivel.
Mixing traps with physical on-ball defense could throw Lillard off his game, as he no longer can be considered just a rookie.