WNBA champ Elena Delle Donne is riding off into the sunset -- she just announced her retirement after 10 seasons.
The 6'5" hooper -- who played for the Chicago Sky and Washington Mystics during her career in the W -- released a statement on her decision ... revealing it's something she contemplated over time before reaching the choice that's right for her.
"One of my favorite children’s books asked, 'How did it get so late so soon?'" Delle Donne said on Friday.
"I have asked myself that over and over again in the process of coming to the decision to retire from playing basketball.