The 24-year-old model is the third black woman to ever be featured on the cover of the annual publication, following Tyra Banks and Beyonce. Herrington tells ET that she's still in disbelief to have her name be affiliated with such powerful women.
"That makes my heart drop because Tyra, Beyonce, they are superstars," she says in praise of the supermodel and singer. "They are what you want to be. They are my idols and they mean so much to me because they have the best work ethic and I feel like ...sorry, I'm emotional. But that's a part of where I get my drive from."
Further gushing over Banks and Bey, Herrington adds, "They set a really good example for my generation and I really want to set a good example like they did for the next generation."
Banks -- who was the first black woman to ever grace the cover of the Sports Illustrated Swimsuit issue -- was the one to break the exciting news to Herrington, and needless to say, the whole ordeal led to lots of tears of joy.
"I was just crying so hard because she is the reason I wanted to be a SI model," Herrington exclaims. "I knew she was the first black model to grace the cover of it, so that was my inspiration."
She adds, "It was the best day. It was the best prank ever."
Check out Herrington on the annual issue of Sports Illustrated Swimsuit when it hits newsstands on Wednesday.
Christie Brinkley's 19-year-old daughter, Sailor Brinkley Cook, is also featured in this SI issue and revealed to ET why she did not tell her supermodel mother that she was posing nude in the magazine.