Golf: Hadwin grabs clubhouse lead at Muirfield, Koepka struggles

July 10, 2020 1:21 AMDUBLIN, OHIO (REUTERS) - Canadian Adam Hadwin birdied his final hole to grab the early clubhouse lead at the Workday Charity Open on Thursday (July 9) while Brooks Koepka, who had not competed since his caddie tested positive for Covid-19 two weeks ago, struggled.