Caroline Wozniacki: 'A hard time'

Tennis player Caroline Wozniacki admitted Thursday on Twitter that she was having a hard time with the end of her engagement to golfer Rory McIlroy, but she received support from a famous friend as Serena Williams reached out with a message of encouragement.

Wozniacki's engagement ended Wednesday, only a few days after the invitations had been sent out.

Williams, ranked No. 1 on the women's tour, replied to Wozniacki.

Appearing uncomfortable and subdued, McIlroy, a two-time major winner, spoke about the decision Wednesday ahead of the BMW PGA Championship only a few hours after announcing the split in a statement.

"It is quite a difficult time for Caroline and myself, and the statement really said it all this morning," McIlroy said at Wentworth. "It was mutual, and we both thought it was the best for us, the best for both of us. Time to move on, and I've said all that I need to say."

The 25-year-old McIlroy and 23-year-old Wozniacki had been dating since 2011. They were engaged on New Year's Eve in Australia.

McIlroy and Wozniacki have been the top-ranked players in their respective sports, but Wozniacki has not won a major title. McIlroy won his first major at the 2011 U.S. Open, then added another a year later at the PGA Championship at Kiawah Island, South Carolina.

The Associated Press contributed to this report.