Brandon Rios tries to revive a young and fumbling career.

Former lightweight title holder Brandon Rio is set to face former interim welterweight titlist Diego Chaves in a scheduled 10-round bout in the main event of HBO's Boxing After Dark this coming August 2 at the Cosmopolitan of Las Vegas, in Las Vegas, Nevada, Top Rank promoter announced.

ESPN.com reports that welterweight Rios after serving a five-month suspension after testing positive for the banned stimulant Methyllhexanamine, will be having his first fight after being dominated by Manny Pacquiao in Macau. He describes the upcoming fight as an extremely important point in his career.

"This is a do or die fight for me," Rios said via ESPN. "I know this fight is very important for my career. I am training extremely hard."

The former champion Rios (31-2-1, 23 Kos) sees himself at the edge of career implosion and that he desparately needs to dominate and convince the critics of his next performance. The twenty-eight year old fighter bowed to his two previous opponents, Pacquiao and Mike Alvarado and displayed horrid form in both matches.

While his camp has tried to find excuses for his recent defeats, his previous outings have critics mumbling if he has any mojo left as a world class fighter. It was not only that he lost in his previous matches but both times he was delegated to a mere sparring partner.

This time, Rios is out to prove detractors wrong.

However, Chaves is not a push-over either. The Argentinian boxer has a reputation of being a powerful puncher who could pose problems to Rios. He won his recent fight via a third round knockout that sent Juan Alberto Godoy to the canvass. He lost his interim belt in a bout to Keith Thurman who also knocked him out in the 10th round of their match in July in San Antonio.

"I know that Rios is a strong and difficult fighter. He is always a straight and a hard puncher," Chaves said. "I am very confident in my boxing skills and I think that with speed and mobility I will win."