Originally the 12th reserve for the Championship, Horsfield received his call-up on Monday when former winner Zach Johnson withdrew following a positive COVID-19 test.
This will be the former University of Florida student’s first Open, but not his first major. He qualified for two U.S. Opens as an amateur and since joining the paid ranks in 2017 he has played in another U.S. Open and this May’s PGA Championship.
Horsfield’s family moved to the United States when he was five and in 2015 he was selected for the Walker Cup at Royal Lytham and St Annes, but withdrew just before the event.
A year later he helped Europe to victory in the annual Arnold Palmer Cup match against America’s top college players and beat this year’s Masters runner-up Will Zalatoris in singles.
He led the European Tour qualifying school at the end of 2017 and last August had two wins in three weeks, at the Hero Open and Celtic Classic.
They swept him from 224th on the world rankings to 80th and he nearly added the Kenya Savannah Classic in March, but missed out on a play-off by one shot.