The heartfelt Instagram post Alex Rodriguez dedicated to his daughter Ella on her 13th birthday comes days after he and Jennifer Lopez announced their split

Happy birthday, Ella Alexander!

Alex Rodriguez's younger daughter is "officially a teenager" as of Wednesday, as her proud father reflected on her life thus far in a heartfelt Instagram post to mark her big milestone.

Alongside his sweet caption, the retired MLB star, 45, shared a photo and video montage of himself with "Ella Bella" and her big sister Natasha, 16, over the years.

Rodriguez's ex Jennifer Lopez also makes brief appearances in the tribute in a few photos he included, as does Lopez's 13-year-old daughter Emme Maribel, and Ella and Natasha's mom, his ex-wife Cynthia Scurtis.

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Alex Rodriguez, Ella
Alex Rodriguez and daughter Ella
| Credit: A Rod/Instagram

"13. Wow. That number has meant a lot to me over the years, but today, it's even more special than ever," wrote Rodriguez, referring to the number he wore during his years playing for the New York Yankees.

"Ella — everyday you amaze me more than I could have ever imagined. You are smart, mature, talented, caring, and funny," Rodriguez praised of his daughter. He went on to say he's "so proud of the young woman" Ella is becoming, and feels "so lucky and grateful to be your dad."

"I love you so much. ❤️ Happy magical 13th birthday sweetheart! 🎂 🎉 🥳," Rodriguez concluded.

RELATED VIDEO: Jennifer Lopez and Alex Rodriguez Officially Call Off Engagement: 'We Are Better as Friends'

Rodriguez and Lopez, 51, released a joint statement on April 15 announcing the end of their engagement after four years together. Multiple sources confirm in this week's issue of PEOPLE, on newsstands Friday, that it was the singer who ultimately broke up with the retired baseball player.

"She insisted on it. There are are too many issues that are unresolved," said a friend of Lopez, who has been filming her upcoming comedy Shotgun Wedding in the Dominican Republic over the past few months.

In the end, sources said, Lopez could no longer fully "trust" Rodriguez, who flew to visit her in the Dominican Republic in March, days after they publicly acknowledged they were working through long-simmering issues.

"She has been pretty miserable," said the friend, "and didn't think it was in her best interests to stay with Alex."