Julio Cesar Chavez Sr, widely regarded as the greatest fighter to come out of Mexico, says heavyweight contender Andy Ruiz must score a knockout in his upcoming fight with Chris Arreola.

Ruiz captured the WBA, WBO, IBF, IBO world titles back in June of 2019, when he pulled off a shocking stoppage win over Anthony Joshua.

But six months later, Joshua dominated Ruiz over twelve rounds for a lopsided decision to recapture the belts.

Ruiz has been out of the ring since suffering that loss.

He would later link up with respected trainer Eddy Reynoso, who is best known as the head coach of Mexican superstar Saul 'Canelo' Alvarez.

Arreola has been away from the ring since August of 2019, when he lost a twelve round war with Adam Kownacki by unanimous decision.

Chavez Sr. views Arreola as the prefect opponent to get Ruiz back on track.

"For me this is a fight where [Ruiz] is simply passing through, because truthfully the fighter [Chris Arreola] does not represent much... he's coming back from a defeat, so I think Andy Ruiz should knock him out," said Chavez Sr. to TV Azteca .

"Chris Arreola, even though he is not a fighter on the level of Andy Ruiz, if Andy Ruiz does not prepare as he should, surprises can happen."

Chavez Sr. believes Ruiz will become a better fighter now that he's being handled by Reynoso and his team.

"From the hand of Eddy Reynoso [Ruiz will improve], although Eddy Reynoso is not a magician either, because the fighter has to do his part in order to ensure things go well. It seems to me that Andy Ruiz is paying attention and he's a fighter who is capable of giving us much more than what he gave in his last fight," Chavez Sr. said.