The USGA has apologized for the "the distraction caused by our decision to wait until the end of the round to decide on the ruling'' following the 1-stroke penalty assessed to Dustin Johnson following his final round of the U.S. Open at Oakmont Country Club on Sunday.

A statement released by the USGA on Monday afternoon read:

"While our focus on getting the ruling correct was appropriate, we created uncertainty about where players stood on the leaderboard after we informed Dustin on the 12th tee that his actions on the fifth green might lead to a penalty,'' the statement said. "This created unnecessary ambiguity for Dustin and the other players, as well as spectators on site, and those watching and listening on television and digital channels.''

On the fifth hole of Sunday's final round, Johnson took a pair of practice strokes next to his ball before a par-putt. As he was preparing to ground his putter behind the ball, the ball seemed to move backward. At the time, he was not assessed a penalty after consulting with the rules official that was following the group. Seven holes later, Johnson was notified that the USGA was taking a look at what happened and would assess it after the round was over.

Johnson was essentially given a 1-stroke penalty and finished the Championship at 4-under-par as he won by three shots over Shane Lowry and others.

"While we respect the viewpoints of those who disagree, our Committee made a careful and collective judgment in pursuit of a fair competition played under the Rules of Golf,'' the statement said.