The Jonas Brothers will have to go without a warm-up act during their international tour.

Singer Demi Lovato -- who had been performing with the boys -- abruptly exited the tour over the weekend to cope with "emotional and physical" issues.

Lovato, who has openly talked about being bullied in her past, reportedly made the decision to seek treatment following a fight with a female dancer.

Due to the timing of her departure, Demi will not be replaced on the last few dates of the tour. The Jonas Brothers are next scheduled to perform in Santiago, Chile on Thursday.