It's been a pretty rough year for Manny Pacquiao. The Filipino boxing icon lost to Floyd Mayweather in one of the most disappointing fights in the sports history. Immediately following the match Pacquiao had to get shoulder surgery, and he will not return to the ring until next year.

Pacquiao will be in the ring again starting next year, but his next opponents remains a mystery. Here are five possible opponents for Pacquiao in his next match

1. Amir Khan

This is the big fight that so many people are expecting to see. Bob Arum has said that Pacquiao is open to facing Amir Khan next year if the two sides agree, which appears to be likely. After his knockout loss to Danny Garcia, Khan has won his last five consecutive bouts. Khan has a huge advantage in the age department, but Pacquiao is obviously the more established and better boxer. Boxing fans would be in for a good fight if these two collided next year.

2. Juan Manuel Márquez

Again? Yes, the Mexican superstar may have to face Pacquiao one more time if he wants that big payday. Juan Manuel Márquez is semi-retired, but he wants to go out with one more good fight. Márquez has 56 career victories with just seven losses. Pacquiao has 57 career wins and six losses. This has been a pretty underrated rivalry over the years. Pacquiao is 2-1-1 against Márquez in their four career bouts, but it was Márquez who had the last laugh with a knockout victory back in 2012. Both of these fighters are clearly past their primes, which is why the fight may indeed happen. This is a chance to settle this rivalry in the ring once last time.

3. Timothy Bradley

"Desert Storm" has already faced Pacquiao twice. The first match ended with an extremely controversial decision, and the second time Pacquiao was victorious. Bradley, now 32 years old, is very quick and he can give anyone problems in the ring with his punching speed. Pacquiao knows he's better than Bradley, but he may want to erase any fan doubt on whether or not he can beat Bradley again. Despite the difference in contracts with Showtime and HBO, Pacquiao and Bradley have shown they can agree on fight dates, rules and contracts very easily. Bradley must first face Brandon Rios this November.

4. Danny Garcia

Just 27 years old, Danny Garcia is quickly rising in the boxing world. Garcia recently made the switch to welterweight division, and he now ranked No. 7 overall. Pacquiao's trainer, Freddie Roach, has already said he prefers Pacquiao to face Garcia next instead of Khan. Speaking of Khan, Garcia knocked him out in the fourth round back in 2012. Garcia is a perfect 31-0 in his young career, and this would be a great opportunity to really showcase his skills in front of the world.

5. Kelly Brook

Mayweather is retired, and the odds of that changing are really slim. Pacquiao will have to search elsewhere. Keith Thurman is out there lurking, but there have been talks between the Pacquiao camp and Kell Brook's team. According to boxing reports, Pacquiao is "interested" in a fight against the English champion. Brook, like Garcia is undefeated in the ring. Brook is just 29 years old and he is the No. 2-ranked welterweight fighter in the world behind only Mayweather. This type of fight would gross hundreds of millions and would be dependent on many factors, such as Pacquiao's health.

Follow Damon Salvadore on Twitter @DamonSalvadore1