Russell Henley used a different type golf ball than the one he started the second round with at the Mayakoba Classic on Saturday, costing him eight penalty strokes and leading to a missed cut.

Henley discovered after the round when autographing golf balls for spectators that he had a different brand of golf ball in his bag and didn't know how it got there. He then determined he had used that ball for four holes during the round -- the ninth through the 12th -- and it was a different type of the Titleist Pro V1x he uses.

The penalty is two strokes per hole, for a total of eight penalty strokes.

Russell Henley was in the top 10 of the Mayakoba Classic after shooting a 69 on Saturday. However, after discovering that he used two different types of golf balls during the round, he was assessed eight penalty shots and missed the cut. Gregory Shamus/Getty Images

"It was a small dash, a different way it was marked that would have been easy to overlook,'' said PGA Tour rules official Brad Fabel, according to pgatour.com. "He came to us and said he didn't know how it had gotten in his bag.''

Fabel said the rules officials on site conferred for more than an hour and also reached out to the United States Golf Association for assistance.

The Rules of Golf permit a player to switch golf balls after each hole, but there is also a local rule that allows a committee to invoke a One Ball Rule, which is typically used at high-level events or professional tournaments. It stipulates that a player must use the same brand and type of golf ball for the entire round.

So, for example, Henley or any player would not be permitted to start with a Pro V1 and switch to a Pro V1x or any other brand or color of golf ball. (The PGA of America, which runs the PGA Championship, does not invoke the One Ball Rule in its competitions.)

Henley, 30, who opened the tournament with a 66, was in the top 10 after what he thought was a 69. The eight penalty strokes dropped him to a 77 and out of the tournament. He is a three-time winner on the PGA Tour.