By Miguel Rivera

Former four division world champion Juan Manuel Marquez believes his career rival, Manny Pacquiao, is still mentally haunted by the brutal knockout loss that he suffered back in the sixth round of their fourth fight in 2012.

That night at the MGM Grand in Las Vegas, Pacquiao was an offensive machine. But he made the mistake of letting his guard down for a split second and jumping in recklessly in the closing seconds of the sixth round - and Marquez landed a picture-perfect right hand that knocked him out cold.

After that fight, Pacquiao has fought with a more cautious style and doesn't throw as many punches.

Marquez watched Pacquiao's fight with Jessie Vargas from last Saturday night and felt the Filipino superstar was unwilling to let his combinations go and very cautious - even against an opponent with a low knockout ratio. Pacquiao still captured the WBO welterweight title with a twelve round unanimous decision win.

"He looks different compared to the Manny Pacquiao we know, with the speed and power," Marquez told Golpe a Golpe. "We saw him get hit by a fighter who doesn't have a strong punch. Jessie Vargas, out of 27 fights has 10 knockouts, so he doesn't have a strong punch but yet he staggered [Pacquiao]."

"I saw a different fighter, more cautious, more thoughtful in his attacks, and that helps [you to ensure that you opponent doesn't knock you out]. We saw [that he is still thinking about that knockout loss], we saw it against Jessie Vargas. Those right hand blows that landed from Jessie Vargas made Manny Pacquiao think. Getting hit with that right hand counter is still fresh in his memory."

"He no longer throws punches thoroughly, so he looks more cautious, fights more from a distance, and he's not looking like he did in the past when he fought with that speed, with this animosity to knock the opponent out. Today we see a more cautious fighter and he's not winning the fights like he used to."