Manny Pacquiao's trainer Freddie Roach has labelled his charge one of the "top five boxers of all time" as he prepares to face Miguel Cotto in his latest bout.

The Filipino meets Cotto on November 14 - a fight which will see the 'Pac Man' bid for his seventh world title at a sixth different weight.

Roach said: "Fighting Miguel Cotto for a seventh world title is going to be unbelievable because Manny is a throwback. He is like a Henry Armstrong type. You don't have fighters like that today that move up in weight like this to win championships in all of these different weight divisions.

"He is carrying his punch and his power with him along with his speed. He is just getting better and better in the ring. This is just one of the greatest achievements ever. He is passing people like Sugar Ray Leonard who was a six-time world champion, Tommy Hearns. He is in the level of the top five fighters of all time of any era."

The Puerto Rican's WBO welterweight belt will be at stake in Las Vegas, although the fighters have agreed a catchweight of 145lbs for the fight - 2lbs below the welter limit.

However, Pacquiao, who previously fought Oscar De La Hoya in a non-title fight at welterweight in 2008, will struggle to go up to the next weight - junior-middle - according to Roach.

Asked if Pacquiao could fight at an even higher weight, Roach replied: "I don't think so. For him to fight at 147lbs we have to feed him five times a day to keep the weight on him.

"I think this will be our final stop but you never know. If something comes at 154 (junior middleweight), maybe we'll go there."

The forthcoming fight has been touted as Pacquiao's toughest to date, but Roach is not so sure and is predicting his man will win by way of knockout.

"I don't know if it is his biggest challenge," he said. "We have fought some great fighters like (Erik) Morales, (Juan Manuel) Marquez and Oscar De La Hoya.

"He's a very good fighter and he is champion of the world. Manny is moving up a weight class but we fought Oscar at this weight. I am very confident in my guy and we are 100 per cent ready for the fight.

"With the power he is punching with right now at this weight, I feel that Manny is going to knock Cotto out. I look forward to the win."

Assessing Cotto's style, Roach added: "Miguel has a good left hook but I don't think he is the strongest that we have faced. (Ricky) Hatton was supposed to be stronger than us also. I have no worries about that because that doesn't win fights. Boxing ability wins fights and Manny is a better boxer than him, so we'll show it on the 14th.

"We are just taking the style of our opponents and making adjustments and he is improving all the time and we are making those adjustments for Cotto's style and his big left hook.

"He is going to be seven-time world champion and he is still learning, still evolving. He is very hungry to improve."