Martina Hingis, who retired in 2002 before making a successful full-time return to the WTA Tour at the start of this year, warned Russia's Anna Kournikova to be fully prepared before pondering a comeback of her own.
"She'd really have to commit herself and grind it out," Hingis told reporters after revealing Kourni-kova offered to reprise their doubles partnership that won the 2002 Australian Open title.
"You can't just play one week and come back. You have to be more professional about it," Hingis said.
The 25-year-old Kournikova, a former world number one doubles player who was ranked in the top 20 in singles from 1998 to 2000, has not played on the tour since cutting her 2003 season short due to a back injury.