The answer will be resolved not later than August, promoter Bob Arum said.
“People are asking how long it will take for a resolution on who Pacquiao will fight next and it’s probably the middle toward the end of August," Arum revealed. “We will have it resolved. Who Manny’s going to fight, when he’s going to fight, and where he’s going to fight."
Soto, a super-featherweight title contender and Valero, an undefeated power puncher, are two of the prime candidates to take on Pacquiao. Until recently, so is de la Hoya.
Oscar de la Hoya, whose next bout is likely his last before retiring from professional boxing, also has a handful of choices for his next opponent. Arum said, One of them is Pacquiao.
“As I understand it based on my discussion with the de la Hoya people, there are four possible candidates. One is Floyd Mayweather Jr., who we know is already retired so I don’t know if he’s really a candidate. Second there’s Felix Trinidad, who I don’t believe is a real candidate because Oscar would have to fight him at a very high weight at, like, 175lbs. So that leaves us with two fighters—Miguel Cotto and Manny Pacquiao," Arum said.
According to the legendary promoter, there are several factors to consider, primary of which is the prize money. Arum added that de la Hoya, a natural 154-pounder, reducing weight won’t be a factor.
“I don’t think the weight is a problem as far as Oscar coming down to 147 is concerned. Based on my preliminary discussions, that wouldn’t be a problem," he said, adding the biggest factor may be what his client’s heart and mind dictate.
Is it Humberto Soto?
Armando Humberto Soto Ochoa is a Mexican professional boxer. Soto won the WBC interim featherweight title by beating Rocky Juarez on August 20, 2005, a fight he 
accepted with two weeks notice. He is known for his unorthodox boxing style, being referred to as a "gumby man" by boxing manager Emanuel Steward.
On November 17, 2007, became the challenger to fight Joan Guzmán, the reigning WBO Super Featherweight champion. Unfortunate for him, Soto lost by unanimous decision.
On June 28, 2008, Soto faced off against Francisco Lorenzo (33-4, 14 KOs) for the vacant interim WBC Super featherweight title. Soto knocked Lorenzo down twice in the fourth round with a barrage of punches. However, after lengthy consultations with officials at ringside, referee Joe Cortez disqualified Soto for hitting Lorenzo after he was down in what appeared to be a grazing punch. Cortez's decision was widely criticized and the WBC refused to award Lorenzo the title.
WBC president Jose Sulaiman condemned the decision as a "gross injustice" and one of the biggest he has seen in a long time. Sulaiman also announced that the WBC board of governors will vote on whether to declare the fight a no contest or to declare Soto the winner by knockout. Lorenzo, therefore, was not presented the green WBC belt as its champion, since it, though, opted to ignore the official verdict, and declared the title vacant. Sulaiman stated he wasn’t seeking to overrule the decision, but: “While we respect the authority of the (Nevada commission) for a decision of the fight, we are the only ones to have the authority to decide on the decision relating to the WBC world title.
Is it Edwin Valero?
Edwin Valero was born on December 3, 1981 in Bolero Alto, Mérida, Venezuela, he is an undefeated southpaw boxer who fights in the super featherweight (130 lb) 
division. His professional boxing record is 24-0 (24 KOs, 19 of which occurred in the first round). Valero is the current WBA super featherweight champion.
Valero started boxing at the age of 12, reportedly compiling an amateur record of 86-6 with 57 knockouts. He was Venezuelan amateur champion three years running, as well as Central and South American Champion (beating Francisco "Panchito" Bojado).
On February 25, 2006, Valero set a new world record by winning his first 18 fights as a professional by first-round knockout (that record has since been broken broken by Tyrone Brunson). The previous record for consecutive first-round knockouts was 15 by Young Otto (record), who accomplished the feat in 1905. In Valero's nineteenth fight (March 25, 2006), Genaro Trazancos ended the first-round knockout streak by surviving until the second round.
Because of his awesome punching power and perfect knockout ratio, he became the darling of hard core boxing fans. His biggest backers in the sport includes Doug Fischer of maxboxing.com (who regularly covers Valero in his articles for the website which also aired videos of his workouts and sparring sessions) and Boxing Inside with Peter Palmiere (Boxing Inside airs on SPTV Channel 33 every Thursday night at 7pm.) The Los Angeles local cable show also aired Valero's workouts, sparring sessions and interviews conducted by journalist Palmiere.
Valero defeated Vicente Mosquera by tenth-round TKO on August 5, 2006. With this win, Valero won the WBA super featherweight title. He has defended the title four times. The last fight was against Takehiro Shimada in Tokyo on June 12, 2008.
Or is it Oscar de la Hoya?
Oscar De La Hoya was born on February 4, 1973 his nicknamed "The Golden Boy", he is a Mexican American boxer and promoter who won a gold medal for the United States Boxing Team at the Barcelona Olympic Games. De La Hoya comes from a boxing family. 
His grandfather Vicente, father Joel Sr., and brother Joel Jr. were all boxers, but it was Oscar who took his boxing talent to superstar status. De La Hoya became Ring Magazine's "Fighter of the Year" in 1995 and Ring Magazine's top-rated Pound for Pound fighter in the world in 1997. De La Hoya has defeated seventeen world champions and has won ten world titles in six different weight classes. He has also generated more money than any other boxer in the history of the sport. De La Hoya's amateur career included 223 wins, 163 by way of knockout, with only 5 losses. He won the United States' only boxing gold medal at the 1992 Summer Olympics, by knocking down his opponent; a win which he dedicated to his deceased mother. De La Hoya is also the founder of Golden Boy Promotions, a combat sport promotional firm. He is the first Hispanic-American to own a national boxing promotional firm and one of only a handful of boxers in history who have taken on promotional responsibilities while still active.
On November 23, 1992, De La Hoya made his professional debut, and in his twelfth professional fight, he won his first title, stopping Jimmy Bredahl in (TKO 10) to win the WBO junior lightweight title. He moved up a division several fights later, defeating Jorge Paez (KO 2) to win the WBO lightweight title, and in his first title defense he defeated former world champion John-John Molina (UD 12). Despite his early success, De La Hoya was criticized, with many dismissing his opposition as weak and noting that he had been knocked down several times early in fights.
This perception begin to change when he faced IBF lightweight champion Rafael Ruelas in a unification bout. Many picked Ruelas to win, but De La Hoya knocked him out in the second round. Then in his next fight, he defeated the undefeated WBC super featherweight champion Genaro Hernandez. Hernandez had criticized De La Hoya heavily going into the bout, but De La Hoya broke his nose in the bout, forcing him to retire after the sixth round. On December 15, 1995, he defeated former champion Jesse James Leija. In total, De La Hoya successfully defended his lightweight title six times.
De La Hoya soon moved up in weight again to challenge WBC junior welterweight champion Julio Cesar Chavez, who was an idol to De La Hoya. Chavez believed he would win easily, as he had broken one of De La Hoya's ribs in a sparring session when De La Hoya was an amateur. But in the fight held at Caesars Palace in Las Vegas, De La Hoya cut Chavez's eye with a jab in the first round, and the fight was stopped in round four due to the cut. Because of this and his later victory over Chavez, De La Hoya has always received criticism from some Mexican fans. In his only defense of this title, De La Hoya defeated previously undefeated WBC lightweight champion Miguel Angel Gonzalez (W 12).
