Ryan Harrison has hired Grant Doyle as his new coach, his agent, IMG's Ben Crandell, confirmed to TENNIS.com. A native of Australia, former ATP player Doyle once coached another American player, Sam Querrey.

Harrison recently parted ways with coach Scott McCain, whom the 19-year-old hired in May and shared with India’s Somdev Devvarman.

Harrison's early 2012 schedule includes tournaments at Brisbane, Auckland and the Australian Open.

Considered one of the United States' brightest young prospects, Harrison finished 2011 with a career-high, year-end ranking of No. 79, but only had a 14-19 record on the ATP Tour. He did score a win over No. 37 Milos Raonic at Indian Wells, qualified for Roland Garros and Wimbledon and reached the semifinals of Atlanta and Los Angeles. However, he did not have a good fall swing. - Matt Cronin