By Lem Satterfield

When southpaw Robert Guerrero was preparing for his August, 2009, IBF super featherweight title bout against Malcolm Klassen, he spent some time sparring with Shane Mosley, who was coming off of a January, 2009, ninth-round knockout that dethroned Antonio Margarito as WBA super world welterweight champion.

The two fighters were in Mosley's quarters in the Big Bear Lakes of California, and Mosley was giving Guerrero advice, such as "give the guy constant movement," and, "use your height to your advantage."

"Robert and I are friends, and we talk every once and a while about life and boxing," said Mosley. "Robert spent some time with me in Big Bear, and I gave him a few pointers."

Guerrero took Mosley's advice and easily defeated Klassen by unanimous decision, 116-113, 116-112, and, 117-111, for the IBF's 130-pound belt.

Now a newly-crowned southpaw WBA and WBO interim lightweight titlist, the 5-foot-9, 28-year-old Guerrero (29-1-1, 18 knockouts) earned his 13th straight victory with last month's uanimous decision over 30-year-old Mike Katsidis (27-4, 22 KOs).

Guerrero told BoxingScene.com recently that he is picking the five-time titlist Mosley to pull a major upset by dethroning 32-year-old, eight-division king, Manny Pacquiao (52-3-2, 38 KOs) as WBO welterweight champion when they meet on May 7 at the MGM Grand Hotel in Las Vegas.

Mosley, of course, agrees with Guerrero.

"Robert and I did so some sparring," said Mosley. "So Robert is speaking from experience when he says I have what it takes to win."

Nearly three weeks ago, BoxingScene.com spoke to 10 of the sport's insiders concerning whom they believed would win the April 16 clash betwen then-WBC king Andre Berto and rising southpaw, former junior welterweight, Victor Ortiz.

Ortiz (29-2-2, 22 KOs) dethroned Berto (27-1 21 KOs) by unanimous decision in over the course of a 12-round, multiple-knockdown drag out brawl. In victory, the 24-year-old Ortiz rose to 5-0-1, with three knockouts since being stopped by in the sixth round in June of 2009 by WBA interim titlist Marcos Rene Maidana (29-2, 27 KOs), who was dropped three times during a bout in which Ortiz hit the canvas twice.

Guerrero was the lone panel member of the 10 to select Ortiz, who was coming off of a 10-round, majority draw opposite the 27-year-old Lamont Peterson (28-1-1, 14 KOs), despite having floored Peterson twice in the third round.

Now, Guerrero is picking Mosley.

"I've got to go with Shane Mosley. Me and Shane Mosley are good friends, and I know that he's up there in Big Bear training really hard. This is Mosley's big opportunity to get back on top, and I just see him doing that. You know, I just like Shane Mosley," said Guerrero.

"You know, he's a good fighter and we're good friends and I know how hard he works. And I think that he's out there in Big Bear getting ready, and I have to go with Shane in this one. There's always that one last fight in that old dog, and Shane Mosley is one of the guys that surprises everybody all of the time," said Guerrero.

"Everybody thought that he was shot before he knocked out Antonio Margarito, and he came out just explosive. I just feel that he's going to come out the same way -- very explosive and hungry and ready to go," said Guerrero. "You know, Manny Pacquiao is fast, and he hits hard, and uses his legs to get in and out. But I think that Mosley has great timing and a great jab, and that's what stops all of that."

A two-time IBF featherweight and one-time IBF super featherweight champion, Guerrero became the interim WBA and interm WBO crowns by vanquishing Katsidis, meaning that he is the mandatory challenger to both 37-year-old WBO and WBA king, Juan Manuel Marquez (52-5-1, 38 KOs), who rose from a third-round knockdown to stop Katsidis in the ninth round of their November bout.