Manny Pacquiao once said that following the third fight with Timothy Bradley Jr. in April, he will close his doors to boxing, but Top Rank's Bob Arum is not convinced with his prized fighter's retirement plan. 

Pacquiao is aiming to focus on his political career and is running for senator in the Philippines come May; that is why he decided to end his career with a fight against another bitter rival in Bradley. 

However, Arum does not want to think that Pacquiao is hanging his gloves for the last time following the rubber match with Bradley. 

"Once that bell rings for that final round, Manny Pacquiao's going to rethink it and who knows if he decides to return?," Arum told Agence France-Presse in Hong Kong. 

Arum continued, "I've been in this boxing business for 50 years and I know that fighters retire and other than, say, Rocky Marciano, they come back."

"Will it be Manny's last fight? I'm not ready to guarantee that," the 84-year-old promoter added. 

In the report, Arum also expressed desire in having another fight between Pacquiao and Floyd Mayweather Jr. 

The two collided last May in the highest-earning fight in the history of boxing, with Mayweather staying undefeated with a unanimous decision victory.

However, Arum cited some factors that need to be ironed out before a second bout between the two happen again. 

"But Mayweather has to un-retire, Manny has to decide whether or not he's elected to the senate and he'll do the rematch, so we'll have to see," Arum explained. 

In the fight versus Bradley, Pacquiao is seeking to get his 58th win and perhaps leave boxing as a champion. 

Bradley is currently a World Boxing Organization (WBO) welterweight champion, and the title is on the line when they face each other at the MGM Grand Garden Arena this April.