Rory McIlroy's bid for a career first FedEx Cup got off to a disappointing start on Thursday as he shot a three-over par 74 in the first round at The Barclays, the opening tournament of the four-event playoffs.

The Northern Irishman, ranked first in the world and first in the FedExCup standings after winning the British Open, WGC-Bridgestone and PGA Championship in succession, trails the leading trio in the clubhouse by eight strokes.

Americans Cameron Tringale, Hunter Mahan and Charles Howell III, all shot five-under rounds of 66 at Ridgewood Country Club to share the clubhouse lead.

McIlroy, starting on the back nine, made a double-bogey and two bogeys before the turn and a birdie on the par-4 fifth hole was canceled out by another bogey on his penultimate hole - the eighth.

But McIlroy slightly limited the damage by finishing his round with a birdie on the ninth hole to end at three-over.

Japan's Ryo Ishikawa and Scotland's Russell Knox were both a stroke behind the leaders after carding 67s.

(Reporting By Simon Evans in Miami, editing by Gene Cherry)