Pacquiao and Mayweather are the two biggest names in the sport, but they have repeatedly failed to agree terms for the most eagerly anticipated fight in recent years.
Roach is preparing the Pac Man for this weekend's clash with Juan Manuel Marquez and insists he remains determined to face Mayweather, but the trainer believes the American is still weighing up his options.
"I still think Manny has some good fights in him," he told Sky Sports News. We still want the Mayweather fight to happen.
"We are kinda waiting for him to come round, but if he doesn't there are other fights out there."
Pacquiao suffered a controversial points loss against Timothy Bradley in June, his first defeat since 2005, and he cannot afford another slip-up in his fourth meeting with Marquez if he is to remain on course to face Mayweather.
The Filipino star was himself the recipient of a contentious points win over the Mexican last year and will be targeting a convincing win, having picked up a split decision victory and a draw in their other fights.
"I'm excited and ready for the fight, ready to rumble," said Pacquiao. "Everything, all is set and in God's hand, what is going to happen on Saturday."