Henrik Stenson has added to the criticism of US Open golf course Chambers Bay after slipping to a four-over 74 on Friday.

Stenson went into the second round with a share of the lead after a 65 on Thursday, but he is now four points off the pace.

"The way we're playing this course in the afternoon compared to the morning, it's borderline laughable at some of the greens and some of the pin positions, when we're actually almost better off plugged in a bunker than being on the top of a ridge, like on the fourth," Stenson is quoted as saying by Sporting Life.

"I kind of lost my patience on the eighth more than anything and hit a lovely shot into nine and was putting down on something that looked like the surface of the moon."

Stenson finished fourth in the US Open last year.