[1] On February 17, 2005, Caballero fought the then unbeaten and would-be world champion Daniel Ponce de León in Hollywood, California.
On November 21, 2008, Caballero knocked out the unbeaten IBF Super Bantamweight champion Steve Molitor in the 4th round at the Casino Rama, Ontario.
Caballero was stripped of his IBF title on February 5, 2010 for failing to have a defense against Takalani Ndlovu, his mandatory challenger in that sanctioning body, in a timely manner.
Celestino was able to schedule a fight with Junior Lightweight Jason Litzau at the MGM Grand Garden Arena in Las Vegas on the opening bout of the HBO Televised undercard of Juan Manuel Marquez vs. Michael Katsidis on November 27.
[needs update] The WBC final Featherweight eliminator ordered by the World Boxing Council between Caballero and the Romanian Viorel Simion (16-0, 7KOs), with the winner landing a shot at current champion Daniel Ponce de León, should have taken place on a date in spring 2013.