"It's a hard time for me right now.Thanks for all the sweet messages!Happy I support Liverpool right now because I know I'll never walk alone," the tennis pro tweeted earlier today.
Her buddy and fellow tennis pro, Serena Williams, tweeted back, "I'll always walk with you."
Wozniacki responded, "aww thank you!"
On Wednesday, the golf pro, 25, revealed that he had split from Wozniacki, 23, a few days ago.
"The problem is mine," McIlroy said in a statement, according to the U.K.'s Telegraph newspaper. "The wedding invitations issued at the weekend made me realize that I wasn't ready for all that marriage entails. … I wish Caroline all the happiness she deserves and thank her for the great times we've had."
McIlroy and Wozniacki announced their engagement on New Year's Eve last year. They began dating in 2011.