However, the Filipino's long-time trainer believes there has been no slide in the seven-weight champion following his knockout loss to Juan Manuel Marquez earlier this year.
"If it does not go well, we will seriously talk about his retirement and possibly going to politics full time," he said.
"It's really hard to say until we see the fight, but I will be the first one to tell him to retire, and we have an agreement that as soon as I tell him that, he will retire."
However, Roach said: "I don't see him slipping in the ring at all."
The duo have been preparing in the southern city of General Santos City, which was not affected by the typhoon that hit the east coast of the Philippines last Friday.
His status as a national hero in the Philippines meant Pacquiao considered leaving the training camp to help relief efforts, but Roach said it was too close to the fight to alter preparations.
"It's way too close to the fight, he needs to double down," Roach added.