For Pacquiao, who was inducted into the International Boxing Hall of Fame last year, this will be a return to the ring after a four-year break. In his last professional appearance, the Filipino lost to Yordenis Ugas.
Barrios last fought in November, fighting to a draw against Abel Ramos. The American held the World Boxing Council championship belt for almost two years.
A rematch between WBC super welterweight champion Sebastian Fundora (22-1-1, 14 KO) and Tim Tszyu (25-2, 18 KO) will also take place as part of the same tournament. Their first fight occurred in March last year and ended with Fundora winning by points.