BRISBANE, Australia -- Trainer Freddie Roach is ready to narrow down Manny Pacquiao's options following the WBO welterweight championship fight against Jeff Horn: Think about another shot at Floyd Mayweather, or think about retirement.
The 11-time world champion is putting his WBO belt on the line Sunday against the 29-year-old Australian, a schoolteacher who is in the biggest bout of his professional career.
"Manny is in a must-win situation. He wants a rematch with Mayweather," Roach said Tuesday at a gym next door to the Suncorp Stadium, where a 50,000-plus crowd is expected for the "Battle of Brisbane."
"With Mayweather you have to look good against an opponent, you have to be impressive."
Roach has been the longtime trainer for the multiple world champion and reckons that Pacquiao, 38, should have a few more big wins in him.
"If he struggles in this fight, it could be over," Roach said.
Asked specifically what the fallout would be if Horn (16-0-1, 11 knockouts) somehow won, Roach said "depending on how he lost, I would probably encourage him to retire."
Not that he's expecting Pacquiao (59-6-2, 38 knockouts) to struggle. Roach said training has consisted of 50 rounds on some days and the preparation -- after a slow start -- has been very intense.
"I expect Manny's best in this fight. I am looking for a big win here," Roach said. "We want to go on to bigger and better things."
Pacquiao lost the 2015 mega fight to Mayweather but has rebounded to beat Tim Bradley and Jessie Vargas on points since then. He wants another shot at Mayweather.
"If there's a chance, why not? I'm willing," Pacquiao said of a potential rematch with Mayweather, who has visited Roach's gym a couple of times -- though not to discuss business. "But let's focus first for this fight. We don't want to underestimate ... Horn, thinking about another fight. This fight is not done yet.
"I know my body. I'm ready. I'm not underestimating (Horn). I'm not taking him lightly. I'm working hard."
Horn turned pro in 2013, the year after reaching the Olympic quarterfinals in London, and has faced 10 top-15 rated boxers in his 17 professional bouts. He hasn't faced anyone of the caliber of Pacquiao, though.
The Pacquiao camp is expecting Horn to come out aggressively in front of his home crowd, and so the preparation has been tailored to that.
A world champion in eight divisions, and now a senator in the Philippines, Pacquiao can still remember the feelings he had ahead of his first big-time bout and is treading carefully because of that.
"That's why we did a lot for this training camp," Pacquiao said. "I know what he's feeling -- being there, being the underdog."
It won't mean he'll take it any easier in the ring.
"All I can say is, it's good he's a teacher," Pacquiao said. "I'm a teacher in the ring."