According to a source close to Mirza, the two are splitting because they have “not got the desired results” over the previous five months, Indian news agency PTI reported. During that span, the pair has lost to teams ranked below the Top 100.
The team enjoyed an incredible amount of success, taking the title at its first tournament, in Indian Wells in 2015. Mirza and Hingis subsequently won three Grand Slams together—the U.S. Open and Wimbledon in 2015, and the Australian Open in 2016—in addition to the 2015 WTA Finals. However, their 41-match winning streak was snapped by Elena Vesnina and Daria Kasatkina in Doha this season, and they have won only one title since then.
It appears that Mirza will begin playing with Barbora Strycova, while Hingis will team with Coco Vandweghe.
"It was question of availability, and also, Barbora Strycova has a good backhand,” the source said, according to PTI. “So they also complement [themselves] game-wise.”
Hingis and Mirza played together at the Rogers Cup in Montreal a week ago. They fell to Christina McHale and Asia Muhammad in the quarterfinals.
Neither player has confirmed that the partnership is ending.