Bannon has been McIlroy's teacher since he was eight years old and a junior player at Holywood Golf Club.
Bannon moved from Holywood Golf Club to Bangor Golf Club, but continued to be McIlroy's coach.
When Rory missed his third consecutive cut at the Memorial two weeks ago, he flew his father and his part-time coach, Bannon, to San Francisco to practice at the Olympic Club, site of the U. S. Open.
He changed agents last year to build a more prominent presence in the United States.
Rory appears to be building his team to become more consistent, win more majors and become a truly dominant player.
His globe-trotting and well publicized romance with tennis star Caroline Wozniacki may have sidetracked Rory for a bit, but he seems to be getting more serious about his golf.
McIlroy is still only 23 years old and has been going back and forth with Luke Donald this year for the No. 1 ranking on the Official World Golf Rankings.