Three-time US Open runner-up Colin Montgomerie has insisted that the greens are "very poor" at this year's tournament.
World number one Rory McIlroy admitted that he struggled with his putting at Chambers Bay, and Montgomerie, who finished the day on one-under par, thinks that the greens are not up to scratch.
He told Sky Sports News: "The green surfaces are very poor, some poorer than others. But no one is going to putt consistently well on these greens."
The 51-year-old also criticised the design of the course, and said that it is not spectator-friendly.
He added: "I feel for the spectators. There are five holes out there where you just cannot spectate, which is bizarre for a course that was supposedly designed for a Major championship.
"There are five holes where you can't see anything. The eighth hole is out of bounds for spectators. It's a helluva walk. You wouldn't walk your dog that far."
Dustin Johnson and Henrik Stenson lead the way after day one.
