Manny Pacquiao: Five Possible Opponents Not Named Floyd Mayweather Jr.

Manny Pacquiao (52-3-2) is always ready for a fight. It doesn't matter who it is. That's one reason why he will be fighting Shane Mosley on May 7th in Las Vegas, Nevada.

It's not necessary to look past the 39-year-old former welterweight champion, but the challenges that remain after Mosley are important for the Filipino superstar's future in the sport.

He doesn't always need to fight the "best" opponents available because he puts on the "best" performances in terms of excitement and energy among boxing fans.

From welterweight to middleweight, these are five challengers Pacquiao could pursue if he makes it past Mosley.

Marcos Maidana (29-2)

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LAS VEGAS - DECEMBER 11: Marcos Maidana of Argentina is lifted up by Sebastian Contursi after Maidana was defeated by Amir Khan of England by unanimous decision in their WBA super lightweight title fight at Mandalay Bay Events Center on December 11, 2010

While a more suitable opponent for Pacquiao could be Amir Khan, who is coming off a unanimous decision victory over Maidana, it's questionable whether they will fight each other while both are training under Freddie Roach. Either way, Maidana is still an exciting opponent for Pacquiao.

This fight could be made because it is a fight the fans would want to see. Maidana doesn't have any notable victories other than against Victor Ortiz, but their styles matchup the best.  If boxing fans just want to see a good fight, look no further than this, as both can brawl and both are tough as nails.

If Maidana is able to look impressive against Erik Morales on April 9th, this could be an intriguing fight and draw a lot of interest among fight fans. It's not as good as Mayweather-Pacquiao, but it's better than a lot of the other fights he will take in the meantime.

Andre Berto (27-0)

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LOS ANGELES, CA - JULY 15: Boxer Andre Berto arrives at the 2009 ESPY Awards held at Nokia Theatre LA Live on July 15, 2009 in Los Angeles, California. The 17th annual ESPYs will air on Sunday, July 19 at 9PM ET on ESPN. (Photo by Jason Merritt/Getty Im

Andre Berto is scheduled to face Victor Ortiz (28-2) in April, but could the winner of that fight be next in line for the Filipino star?

Ortiz will be Berto's toughest test to date and a proving ground for future fights against the bigger names in the sport.

Berto started his pro career in the junior middleweight division. He is a stalky, fast boxer who throws vicious uppercuts and excellent combination. He leaves his chin open,and this is what makes him an intriguing challenge for Pacquiao, not to mention he is also unbeaten.

If Pacquiao fights at 147, it's going to come down to two or three opponents. Berto is one of them.

Timothy Bradley (27-0)

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NOTTINGHAM, ENGLAND - MAY 10: Timothy Bradley celebrates his win against Junior Witter for the WBC Light Welterweight fight on May 10, 2008 at Nottingham Ice Arena in Nottingham, England. (Photo by John Gichigi/Getty Images)

Bradley is coming off the biggest win of his career against the undefeated Devon Alexander in January. It was a sloppy fight that ended by a headbutt delivered by Bradley. The technical decision was ruled unanimously for Bradley in the 10th.

There is only one reason this fight wouldn't happen: headbutts. This is a common occurrence in Bradley's fights and Pacquiao is vulnerable when it comes to getting cut around the eyes.

What makes the fight interesting is the drive of both fighters to be great. Bradley is known for being one of the hardest workers in the sport and his body and fights show it. His determination is higher than most boxers in the sport today.

Sergio Martinez (46-2-1)

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ATLANTIC CITY, NJ - NOVEMBER 20: Sergio Martinez enters the ring against Paul Williams for the Middleweight Championship fight on November 20, 2010 at The Boardwalk Hall in Atlantic City, New Jersey. (Photo by Al Bello/Getty Images)

This is a fight that is not likely to happen, but Pacquiao would have no problem accepting it. If anything is going to keep him from moving up to 154 pounds to fight the middleweight champion of the world, Sergio Martinez, it's going to be his trainer, Freddie Roach, or his manager, Bob Arum.

Both expressed interest in fighting each other and it would be the best challenge Pacquiao could take on that isn't named Floyd Mayweather Jr. Martinez is coming off the "Knockout of the Year" against Paul Williams. He also holds a win over Kelly "The Ghost" Pavlik earlier that year.

Martinez wouldn't back down against Pacquiao's attack and this fight would produce fireworks for anyone who likes to see a good fight. It has all the makings of a "Fight of the Year."

Juan Manuel Marquez (52-5-1)

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LAS VEGAS - JULY 31: WBA/WBO lightweight champion Juan Manuel Marquez (R) hits Juan Diaz in the eighth round of their bout at the Mandalay Bay Events Center July 31, 2010 in Las Vegas, Nevada. Marquez retained his WBA and WBO lightweight championship bel

Juan Manuel Marquez deserves the shot against Pacquiao more than any other fighter right now; probably even more than Mayweather at the moment.

Their first two meetings were close and controversial and Marquez has been looking for a third meeting since the last time they met in 2008.

Marquez is coming off a "Fight of the Year" candidate against Michael Katsidis. Marquez got off the canvas in the third round and knocked the Australian fighter out in the ninth round. It was another classic by the Mexican fighter and proved he was ready for Pacquiao.

This will be one of the biggest fights of the year if it happens in 2011 and it is tentatively scheduled to take place in the fall if Pacquiao defeats Mosley.