Serena Williams Pens Heartfelt Note to Unborn Child: 'I Can't Wait to Meet You'

Serena Williams has a message for her baby.

Read: Serena Williams Was Pregnant When She Won Australian Open

The tennis great posted a picture on Instagram along with a note: “My dearest baby, you gave me the strength I didn't know I had. You taught me the true meaning of serenity and peace. I can't wait to meet you.”

She posted the note, along with an image of her on the beach Monday morning.

She added: “I can't wait for you to join the players box next year. But most importantly, I am so happy to share being number one in the world with you.... once again today.”

Read: Tennis Courtship: Serena Williams Shows Off Her Giant Diamond Engagement Ring

The tennis ace announced that she was 20 weeks pregnant last week with her first child.

Williams, 35, is expected to deliver her baby in the fall and will not compete in any tennis tournaments for the remainder of the year.

She is engaged to Reddit co-founder Alexis Ohanian, who is the father of the child. There have been no public details as to when they will get married.

Watch: Actor Bradley Cooper and Model Girlfriend Irina Shayk Welcome First Child: Reports