"James Harden is laying down his own challenge.

The Oklahoma City Thunder guard wants to crack the starting rotation next season.

"I hope so," said Harden, last year's No. 3 overall pick. "That's what this summer is for."

For Harden, this year's appearance at summer league in Orlando is about development and turning his shortcomings in to strengths. But it's also about showing the coaching staff, himself and his teammates that he's ready to step up and be in the starting unit.

Holding him back has been the defensive side of the ball, where Thabo Sefolosha excels and Harden still is honing in on what it takes to be a two-way player. In the Thunder's 87-82 win over Boston on Monday, Harden displayed how much more of a pest he's become. Albeit against an overmatched but scrappy Celtics squad, Harden provided the game-clinching block on Jaycee Carroll, the end of an impressive defensive sequence that became a staple in the Thunder's come-from-behind win.

"It needs to improve every single day," Harden said of his defense. "I need to show them that I can really get after it and that I improved over the past year and into this summer. That's the key. Our whole motive is defense."

Harden said his biggest improvement, though, has been the natural progression that comes with players growing more familiar with the game. It's an aspect that will be critical for Harden to master next season.

Despite averaging 9.9 points, 3.2 rebounds and 1.8 assists a year ago, Harden struggled at times being the fourth option behind Kevin Durant, Russell Westbrook and Jeff Green. To adjust, Harden said he's worked to incorporate more playmaking skills into his game so that he isn't solely a spot-up shooter. He wants to be more aggressive whenever he's on the court rather than being a passive player who pacifies too often."