By Edward Chaykovsky

WBC/WBA welterweight champion Floyd Mayweather Jr. has never tasted the canvas from a legit knockdown. He voluntarily went to a knee, to get a breather, after suffering a hand injury during his fight with Carlos Hernandez. A few years later, he got tagged with a good shot and his glove appeared to touch the mat in the 2006 clash with Zab Judah - but the ref overlooked it. 

WBA 'regular' welterweight champion Keith Thurman will not be surprised if Mayweather tastes the canvas in his upcoming fight with WBO king Manny Pacquiao on May 2nd at the MGM Grand in Las Vegas. 

"I’ve told people before talking about this fight, don’t be surprised if Manny Pacquiao scores a knockdown. You got to understand that scoring a knockdown doesn’t always mean that the guy was really-really-really hurt. It just meant that you caught him at the right time, his feet were a certain way, and the dude fell over when you hit him. That’s a knockdown," Thurman told On The Ropes Boxing Radio .

While Thurman predicts a knockdown in favor of Pacquiao, that doesn't necessarily mean that he thinks the Filipino superstar will win the fight. In order to win, Thurman says Pacquiao will need several knockdowns to pile up the points on the scorecards.

"I think Manny is going to need a knockdown — not just a knockdown, possibly more than one knockdown to win the fight. I made that statement as well, that Manny Pacquiao needs at least two knockdowns to win the fight," Thurman said.