NEW YORK—Due to injuries and scheduling, Caroline Wozniacki didn’t do much training with former coach David Kotyza. But the 26-year-old has reiterated that it was his decision to stop working with her, not the other way around,

"It wasn't my decision,” Wozniacki said after her first-round win over Taylor Townsend at the U.S. Open. “I know there have been a lot of rumors. He has a three-year-old son, and it's at the point where the son is old enough to understand that his dad is away."

Wozniacki, who is coached by her father, Piotr, has brought in several coaches during her career, but the partnerships have rarely lasted for long periods.

The pair began working together at the beginning of the clay-court season. Wozniacki said the partnership was too limited to have a big impact on her game.

"A week into it, I broke my ankle,” she said. “We had just done some technical things.”

The former world No. 1 from Denmark played four tournaments during the grass-court season, including a first-round defeat to Svetlana Kuznetsova at Wimbledon.

Following Wimbledon, she added that "he went on vacation for a little while, then we stopped.

"He's a good guy and he had some good inputs,” Wozniacki said, “but I don't feel like I worked with him for long enough."

Wozniacki is No. 74 in the rankings.