Former unified world champion Jeison Rosario believes Brian Castaño has an extremely tough task ahead of him when he meets Jermell Charlo for the undisputed world super-welterweight title in San Antonio on Saturday evening.

WBO title holder Castaño is a live, 9/4 underdog for the clash to decide the world’s premier 154-pounder. But Dominican puncher Rosario, who lost his WBA Super and IBF crowns to WBC champion Charlo by eighth round KO in September 2020, says Castaño needs to be crafty or he will suffer a similar fate.

From first-hand experience, Rosario says the right-hand work of Charlo presents the most serious danger ahead of tonight’s encounter in Texas.

“Charlo has power in both hands, but his right hand over the top is his best punch, and I think Charlo is going to hurt Castaño with that punch throughout the fight. Charlo’s right uppercut is another big weapon for him,” Rosario told ESPN.com.

“Castaño needs to have the fight of his life, make a major effort to stay away from Charlo’s right hand. He is facing a very strong fighter, who has a lot of experience and is much bigger than him. Castaño has to be cautious when going in to put pressure. If he can avoid Charlo’s punches and close the distance, and punch inside, he can get a good result.

Charlo’s [right] hand seems to me to be a big key in this fight. That’s the hand that hurt me when I fought Charlo. If he connects that blow, he is likely to end the fight early.

If Castaño takes unnecessary risks and starts to exchange punches in the middle of the ring with Charlo, I think Charlo will knock him out. But if Castaño moves well and picks his moments to attack, he could frustrate Charlo a bit. However, that won’t be enough for him to win.”

Main image: Amanda Westcott/Showtime.