MELBOURNE (Reuters) - Ash Barty's brilliant year on the tennis tour has not shielded her from bouts of homesickness but the Australian is determined to keep working and stay world number one through the U.S. Open and beyond, coach Craig Tyzzer said.

The 25-year-old stayed home in Queensland in 2020 as COVID-19 spread around the world but she returned to the tour this year to claim Wimbledon and four other titles.