"Morales will dominate in an easy fight," said Barrera in an interview with popular boxing website SecondsOut.
Barrera downplayed Morales’ listless 12-round loss to unheralded Zahir Raheem in September, saying his compatriot was not motivated and did not train hard aside from fighting too heavy (weighing in as a lightweight).
But Pacquiao, who stopped Hector Velazquez in the fifth round in the undercard of the Morales-Raheem fight, remains unfazed.
"It will be a different outcome this time. There will be no let-up," Pacquiao said in Filipino before he departed for the US to resume his training under renowned trainer Freddie Roach for the keenly-awaited fight dubbed "The Battle" at the Thomas & Mack Center in Las Vegas.
Meanwhile, Barrera said he is looking forward to fight the winner of the Morales-Pacquiao rematch midway next year.
"I want to fight the winner of (next month’s fight) and I think that will be Morales," said Barrera.
This developed as Morales, now training at the Queretaro in Mexico, announced that Jose Luis "Maestro" Lopez Sr will replace his father Jose Morales as the chief tactician for the Pacquiao return showdown.
The Durango, Mexico native Lopez, himself a former boxer who now manages his son, is highly respected for having steered him to the world championship.
"We are already working together and he helps me to work with the mitts," said Morales, who is now on the third week of training in the Querétaro, in an interview with Box-Latino.
The three-time world champion also divulged that his camp is already complete with the arrival of sparring partners Manuel "Pirri" Leyva and Mauro "Betillo" Gutiérrez III in addition to Osvaldo Alvarado, Jorge Quezada, Francisco Nava and Refugio Tiscareño. The group’s physician is Dr. Mario Sanchez.