By Miguel Rivera

Former four division world champion Jorge Arce is not convinced that Manny Pacquiao, an eight division title winner, is 100% natural. The Mexican star is under the belief that Pacquiao is using an undetectable substance to improve his performance and increase his mass. Arce questions Pacquiao's record breaking ability to start his career at 106-pounds and win titles at welterweight and junior middleweight. 

"Pacquiao is getting something, that's for sure. He never [comes up] positive [during drug tests], so it is logical that he is using something that is legal or not detectable in his urine. Because I remember when Pacquio did not want to fight [Floyd] Mayweather, because [Mayweather] said that he wanted to have doping tests [involved in their fight] and Manny refused to have them. Pacman is coming from [the] flyweight [division] and walks around at welterweight. I am convinced that Manny is getting something, but it is not detectable. I've seen him overwhelm [fighters] who are much bigger than him," Arce said.