World No. 1 Rory McIlroy apologized Wednesday for walking off the course in the middle of his second round at last week's PGA Honda Classic, saying he learned from the error and will not do it again. On the eve of playing his first round at the $8.75 million World Golf Championships Cadillac Championship at Doral alongside World No. 2 Tiger Woods and England's Luke Donald, McIlroy said he made a big blunder by leaving early. "I realized pretty quickly that it wasn't the right thing to do," McIlroy said. "No matter how bad I was playing I should have stayed out there."