Demi Lovato
Demi Lovato arrives at the 2011 National Council of La Raza ALMA Awards in Santa Monica, California, Sept. 10, 2011. Reuters/Gus Ruelas

Ariana Grande is out and Demi Lovato is in as the headliner of this year's Major League Baseball (MLB) All-Star Game concert in Cincinnati on Saturday. An excited Lovato shared the news with her fans on Twitter.

"I'm so excited to be headlining the MLB All-Star Concert," Lovato wrote. "I hope my fans in Cincinnati are ready to get ‘Cool for the Summer'!"

Grande had to cancel her concert appearance because of a wisdom tooth removal. The “Problem” singer expressed her disappointment on Twitter, saying she feels miserable.

"Demi Lovato is one of today's best young artists and we know she will provide fans with a fantastic experience they won't soon forget," Tony Petitti, chief operating officer of Major League Baseball, said in a statement, according to Reuters. "We're disappointed that Ariana Grande cannot partake in the All-Star festivities, but wish her a speedy recovery.”

British rock band Rixton, best known for the hit song, "Me and My Broken Heart,” are also listed as performers.

Meanwhile, Grande recently made news for her “I hate Americans. I hate America” remarks. The singer and her rumored love interest Ricky Alvarez were buying doughnuts in a California shop when she made the controversial remarks. The 22-year-old has since issued an apology. "I am extremely proud to be an American and I've always made it clear that I love my (country)," the statement said, according to BuzzFeed. "What I said in a private moment with my friend, who was buying me donuts, was taken out of context and I am sorry for not using more discretion with my choice of words."

Grande went on to explain that her remarks were focused on how Americans eat fatty foods like doughnuts “without giving any thought to the consequences that it has on our health and society as a whole.” She also went on to explain that she is worried about “childhood obesity.”