Rory McIlroy has withdrawn from this week's RBC Heritage at Harbour Town, after the world number three failed to make the cut at the Masters last week.McIlroy's bid for a career Grand Slam ended when he shot a disappointing second-round 77 after being a favorite to win his first Green Jacket at Augusta National heading into the major.McIlroy will not be replaced by an alternate, with the field reduced to 143 players for the tournament on Hilton Head Island, where Jordan Spieth is the defending champion.The 33-year-old who captured the last of his four majors in 2014, had been hoping to win the Masters so that he could join Gene Sarazen, Ben Hogan, Jack Nicklaus, Gary Player and Tiger Woods as the only players to achieve the career Grand Slam.