By Larry Fine (Reuters) - Great talent can be a burden as much as a blessing and great expectations weigh on Northern Irishman Rory McIlroy at this week's U.S. Open at Merion in the Philadelphia suburbs. McIlroy, whose resounding wins at the 2011 U.S. Open at Congressional and last year's PGA Championship on Kiawah Island and a climb to the number one ranking cemented him as golf's next prodigy ...
