Clayton Kershaw is determined to return to the Los Angeles Dodgers this season and be a difference maker.

"I'm trying to make it back to have an impact on this season for our team," Kershaw said. "I don't know what that means exactly."

Kershaw hasn't pitched since June 26 because of what was first diagnosed as a mild disk irritation in his lower back, but that was before a setback during a simulated game that has left his return date unknown.

The left-hander had a 1.79 ERA over his first 16 starts and had 145 strikeouts in 121 innings.

Kershaw's setback occurred after he threw in a simulated game at Dodger Stadium on July 16.

"I just knew there was something that was not right," he said. "I definitely felt it where I shouldn't have felt it."