Cameron Smith has withdrawn from this week's BMW Championship, the penultimate event of the 2021-22 PGA Tour season, amid reports he is set to defect to LIV Golf.

The Australian, who claimed his first major at The Open Championship last month at St Andrew's, has pulled out citing discomfort in his hip.

It means Smith, currently number three in the FedEx Cup rankings, will miss out on the final event before the season-concluding Tour Championship at East Lake.

"Unfortunately, Cam will be unable to compete in the BMW Championship this week in Wilmington," agent Bud Martin said. "He has been dealing with some on-and-off hip discomfort for several months and thought it best to rest this week in his pursuit of the FedExCup."

The Brisbane native struggled last week at the FedEx St. Jude Championship, where he was handed a two-stroke penalty for playing from the wrong place and, having challenged for the lead at one stage, finished tied for 13th.

Now, he will likely drop further away from the chance to dethrone Scottie Scheffler, particularly if the rumblings about a switch to the breakaway LIV Golf series prove well-founded.