Masters 2017: Phil Mickelson says top players are loose in ball marking

American Phil Mickelson has won the Masters three times

Some leading players on the PGA Tour are "intentionally loose" in marking their ball, says Phil Mickelson.

American Lexi Thompson ended up losing the first women's major of the season after incorrectly replacing a marked ball and earning a four-stroke penalty.

Thompson said she did not mean to move the ball, but Mickelson says it does happen deliberately on the men's tour.

"They will move the ball two, three inches in front of their mark," said three-time Masters champion Mickelson.

"This is an intentional way to get it out of any type of impression and so forth - and I think that kind of stuff needs to stop."

Incorrectly replacing a marked ball incurs a two-stroke penalty under R&A rules.

Thompson, 22, incorrectly replaced a marked ball in the third round of the ANA Inspiration last weekend with a TV viewer spotting the offence and telling officials by email.

She was given a further two-stroke penalty for returning an incorrect scorecard.

Thompson was left in tears when told of the penalty while leading Sunday's final round by three shots - and then lost a play-off to South Korea's Ryu So-yeon.

Mickelson, 46, says no golf tournament should be decided in such a manner, believing the decision should be reversed and Thompson declared the winner.

"I think that she should be given the trophy," he said.

"I feel like we've all kind of been a little lax at times in the markings of our golf ball and I hate to see it cost somebody a major championship because of that."