Golf star Rory McIlroy has received a warning that he may not be able to skip the FedEx Cup's opening playoff event indefinitely.

The PGA Tour FedEx Cup Playoffs begin on Aug. 7 with the FedEx St. Jude Championship at the TPC Southwind in Memphis. Except No. 2 Rory McIlroy, all of the players among the top 70 on the points list are present and ready to go. Cameron Young's victory last week in the Wyndham Championship capped the regular season.

Reigning Masters champion Rory McIlroy decided to sit out of the FedEx St. Jude Championship, a decision that has stirred controversy within the PGA Tour and has one PGA Tour official "very concerned."