AKRON, Ohio — Back at Firestone Country Club for the first time since he won the 2014 World Golf Championships-Bridgestone Invitational, Rory McIlroy enthusiastically took to the South Course on Wednesday for a practice round ahead of the last WGC event of the season.

Under plenty of sunshine, McIlroy’s swing was in full flight on the tree-lined course he counts among his favorites. He was pacing off distances, jotting down notes in the yardage book and consulting his coach, Michael Bannon, throughout the 18 holes.

Nothing really seemed out of the ordinary except for the man carrying the bag — Harry Diamond, McIlroy’s best mate from childhood and best man at his wedding earlier this year.

McIlroy split with his longtime caddie, J.P. Fitzgerald, two days after finishing in a tie for fourth at the British Open at Royal Birkdale. McIlroy, winless this season, won four majors and 26 titles with Fitzgerald on the bag. He paid tribute to…