Boxing fans around the world have been eagerly waiting for Manny Pacquiao to announce his 9 April bout opponent, after which the Filipino boxer is set to retire.

A number of names of potential opponents has been doing the rounds, and US boxer Terence Crawford and the UK's Amir Khan are being touted as top contenders.

Floyd Mayeather Sr, who took a dig at Pacquiao a number of times before the fight of the century against Mayweather Jr in May, talked about the two contenders and said he felt Pacquiao could lose his final bout if he squared off against Crawford.

"I think Crawford can beat Pacquiao. Amir Khan's got a glass jaw, if you look at him too long, he's gonna fall down. We'll see, but if Pacquiao hits Amir Khan good, Amir Khan's gone," Maywather Sr told ontheropesboxing.com.

Irrespective of the opponent — Crawford or Khan — Pacquiao faces in his farewell fight in April, the bout is expected to be a humdinger of a contest. One does not need rocket science to understand Khan's deep desire to face Pacquiao. Khan is said to have come close to a fight against Pacquiao in the past, but the bout did not materialise. This is Khan's final chance to fight the Filipino.

It is not going to surprise anyone if the Filipino ignores Khan and goes ahead with a bout against Crawford, who knows he has a chance of facing Pacquiao. Crawford is waiting to hear from the Filipino about his farewell bout opponent.

Pacquiao's retirement will leave a gaping hole in the sport as Floyd Mayweather Jr retired from the sport in September after defeating Andre Berto. With Mayweather's victory over Berto, the American has equalled Rocky Marciano's record of 49-0.

"When Floyd said goodbye, he said goodbye to Pacquiao and everybody else. Unless Floyd decides to come back and do something that who knows what, because to me there's no reason to fight nobody. He needs to stay right there with the Rocky Marciano record. He can surpass that record but if he wants to surpass it, I think he should do it within a year," said Mayweather Sr.